These flavorful stuffed onions are a unique and easy side dish! Tender, sweet onions get filled to the brim with hot Italian sausage, juicy tomatoes, and cheese, and baked in the oven.
I love making stuffed onions as a fun riff on stuffed peppers. For another easy variation, give my stuffed tomatoes a try, next.
I think every cuisine has its own variation of stuffed onions. There’s Greek salantourmasi and Turkish sogan dolma (both of which remind me of Macedonian sarmi, or cabbage rolls). Meanwhile, the stuffed onions recipe I’m sharing today is definitely Italian-inspired. We’re stuffing sweet onions with a juicy combination of spicy sausage and tomatoes, topped with a melty Italian cheese blend.
Even my husband, who firmly believes that onions belong in his favorite tomato salad or diced up and hidden in his food, raves about this whole stuffed version.
What Makes These Stuffed Onions So Great
- An easy side dish. Along with my roasted eggplant stacks, these stuffed onions are one of my go-to vegetable side dishes whenever we entertain. They look impressive on a plate, but they’re SO simple to make.
- Lots of flavor. If you love onion rings and Italian sausage, I already know you’re going to love this stuffed onion side dish! While they aren’t breaded, the onions are sweet and tender, packed with a flavor-loaded, meaty filling and melty cheese.
- Make them your own. You can swap the filling with different ground meats, veggies, and cheeses to suit your family’s tastes. It’s also easy to play around with seasonings, herbs, and more add-ins. The sky’s the limit. I include some ideas further on.
Recipe Ingredients
Fun fact: Hunt’s® Diced Tomatoes were the original inspiration for this recipe, and I’ve tweaked it here and there over the years. The ingredients are super simple, and I’ve included some notes below. Scroll down to the recipe card after the post for the printable recipe instructions and full ingredient amounts.
- Onions – The best onions for stuffing are sweet varieties, like Walla Walla or Vidalia onions. These are less pungent than other onions. You’ll find them in most major grocery stores. Try to find medium-sized onions, as they’ll be easier to fill.
- Tomato Sauce – Choose your favorite store-bought or homemade tomato sauce (my favorite is still Hunt’s®). Marinara sauce or passata also works well here.
- Italian Sausage – Sweet or hot Italian sausage, whichever you prefer. I use lean turkey sausage, but you can also use another kind, like pork.
- Garlic – Fresh cloves, chopped.
- Diced Tomatoes – You can leave these undrained.
- Cheese – Feel free to use a blend of grated Italian cheeses. Good options are parmesan, pecorino, mozzarella, and provolone.
- Breadcrumbs – I like to use panko breadcrumbs since they’re larger, with a crunchier texture. Regular breadcrumbs (seasoned or unseasoned) also work.
How to Make Stuffed Onions
I have a sort of obsession with stuffing. Not Thanksgiving stuffing (OK, maybe that, too), but stuffing foods with even more delicious ingredients! I’ll stuff just about anything, from jambalaya stuffed peppers to eggplant and mushrooms.
Whichever veggie I choose, the method is more or less the same. Here’s how to put together these saucy Italian sausage stuffed onions:
- Trim and steam the onions. Start by trimming ¼” from the top of the onions, and trim the bottom so that the onions stand upright. Then, microwave the onions in two batches with a little water so that they steam and soften (in my microwave, it takes about 12 minutes per batch).
- Hollow out the middle. Once the onions are cool enough to handle, use a sharp knife to carefully cut out the middle layers of each onion, leaving about ¼” thickness around the edges. Chop up and set aside about 1 cup of the removed onion for the filling. Save the rest for a stir-fry, salad, or frittata!
- Fill the pan. Now, spread tomato sauce into the bottom of a greased casserole dish. Arrange the onion shells over the sauce. Give that a quick season with salt and pepper.
- Prepare the sausage filling. Meanwhile, brown the sausage in a skillet. Add garlic and the reserved chopped onions, followed by tomatoes, the rest of the tomato sauce, ½ cup of cheese, and breadcrumbs. Stir everything together.
- Stuff the onions. To stuff your onion shells, spoon a bit of filling into each onion. It’s fine if a little spills out here and there, but do your best.
- Bake. Finally, cover the baking dish with the stuffed onions in foil. Bake at 375ºF for 15-20 minutes, and once they’re warm and bubbly, sprinkle the tops of the onions with the remaining cheese. Tada! Baked stuffed onions, ready to serve.
Tips and Variations
- Use the right onions. I highly, HIGHLY recommend sweet onions for this recipe. While yellow or brown onions will work in a pinch, the flavors aren’t quite the same. Sweet onions have a much milder flavor. Also, on the subject of onions, be sure to select onions similar in size. This way, they’ll cook through evenly.
- Steam in batches. Use a microwave-safe dish, and microwave the onions in batches. Make sure there’s about ½ cup of water in each batch so that they steam.
- Save the pan sauce! All that tomato sauce left over in the baking dish is delicious to drizzle over the onions when serving.
- Swap the sausage. In place of Italian sausage, you can use plain ground turkey, chicken, ground beef, or pork. If you’re using regular ground meat, I recommend adding in a few pinches of Italian seasoning to taste, to boost the flavors. You could also borrow the meat mixtures from my pork meatballs and air fryer meatballs.
- Different cheese. Any melty cheese works great in this recipe. If you don’t have an Italian blend, substitute it with shredded cheddar, Monterey Jack, Gouda, or Swiss cheese. I think a French onion soup-inspired variation filled with savory ground beef and topped with Gruyère cheese would be delicious!
- More add-ins. Customize the filling any way you’d like with mix-ins like capers, olives, pine nuts, spinach, and herbs like oregano, basil, rosemary, thyme, and Italian seasoning. If you like a bit of extra kick, add crushed chili flakes or cayenne.
What to Serve With Stuffed Onions
I serve these stuffed onions warm, drizzled with the leftover tomato sauce in the baking pan. They’re a great side dish or appetizer for any occasion, but I especially love making these when we have friends or family over. Stuffed onions go great with chicken chasseur or chicken saltimbocca, and beef dishes like coulotte steak or steak kabobs. I’ll also make these as a “fancy” side to braised lamb shanks and mashed potatoes during the holidays!
Storing and Reheating Leftovers
Refrigerate. If you have leftover stuffed onions, store them in a single layer in an airtight container and refrigerate them for up to 4 days.
Reheat. Warm up these sausage stuffed onions in a 350ºF oven under foil for 15-20 minutes until they’re hot throughout. The microwave is another option, just reheat in 30-second intervals.
More Vegetable Side Dishes
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Prep. Preheat the oven to 375°F. Spray a 13×9-inch baking dish with cooking spray.
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Trim the onions. Cut a ¼-inch slice from the top of each onion. Trim a small amount from the bottom end so each onion stands upright.
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Microwave the onions. Place half of the onions in an 8×8-inch microwave-safe dish. Add 1/2 cup water and cover. Microwave on HIGH for 12 minutes, or until the onions are tender. Carefully remove onions from the dish and cool slightly. Repeat with remaining onions and water.
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Hollow out the centers. When cool enough to handle, carefully remove the inner layers of the onions with a paring knife, leaving about ¼-inch around the edges. I remove about 3 to 4 layers from each onion, depending on the size of the onion. Chop and reserve 1 cup of the onion for the filling. Set aside the remaining onion for another use.
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Fill the pan. Next, spread 1 cup of tomato sauce into the bottom of the prepared baking dish. Arrange prepared onion shells over tomato sauce. Sprinkle with salt and pepper and set aside.
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Cook the sausage. Heat a large nonstick skillet over medium-high heat. Add sausage; cook 4 to 5 minutes or until crumbled and no longer pink, stirring occasionally. Drain the excess grease.
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Make the filling. Add the reserved 1 cup of chopped onion, then garlic, and cook for 2 to 3 minutes or until fragrant. Stir in undrained tomatoes, remaining tomato sauce, ½ cup cheese, and bread crumbs. Stir to combine.
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Stuff the onions. Spoon the sausage mixture into the prepared onion shells.
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Bake. Cover the baking dish with aluminum foil. Bake for 15 to 20 minutes or until heated through. Remove from oven and sprinkle the remaining ½ cup cheese on top of the onions. Afterward, serve the stuffed onions with a little sauce from the dish.
Serving: 1Onion | Calories: 190kcal | Carbohydrates: 27g | Protein: 10g | Fat: 5g | Saturated Fat: 0g | Cholesterol: 23mg | Sodium: 280mg | Potassium: 473mg | Fiber: 3g | Sugar: 16g | Vitamin A: 20IU | Vitamin C: 16.7mg | Calcium: 96mg | Iron: 1.3mg
Nutritional info is an estimate and provided as courtesy. Values may vary according to the ingredients and tools used. Please use your preferred nutritional calculator for more detailed info.
