This post may contain affiliate links learn more

If you’ve only ever thought of onions as a background flavor, get ready to have your mind blown. This Cheesy Stuffed Onion Casserole turns humble onions into the star of the show, stuffing them with a savory mix of ground meat, rice, herbs, and mushrooms, then baking them until tender and bubbling under a cheesy crust. It’s a dish that’s both rustic and impressive, perfect for a cozy family dinner or even a dinner party where you want to serve something unexpected. The sweet, mellow flavor of baked onions pairs beautifully with the richness of the filling, creating a casserole that feels hearty but still balanced.

Full Recipe

Ingredients

300 g ground meat (beef, pork, or a mix)
Salt and black pepper to taste
1 tsp dried paprika
50 g uncooked rice
100 ml water
1 bunch parsley, chopped
1 bunch green onions, chopped
1 carrot, finely diced
1 tbsp tomato sauce
2 tbsp soy sauce
1 tbsp olive oil (plus extra for brushing)
6 medium onions (whole, peeled, tops trimmed)
40 g butter (plus extra for brushing)
1–2 cloves garlic, minced
300 g mushrooms, chopped
3 medium tomatoes, diced
100 ml cream
1 tbsp sugar
1/3 tbsp balsamic vinegar
2 eggs, beaten
200 g cheese (mozzarella, gouda, or your choice), grated
1–2 additional tomatoes for garnish slices
1 clove garlic (for cheese layer)
Mayonnaise to taste (optional)

Directions

Prepare the rice and meat mixture – In a bowl, combine the ground meat with salt, black pepper, and paprika. Add uncooked rice and water. Stir in chopped parsley, green onions, and carrot. Mix until well combined, then stir in tomato sauce, soy sauce, and olive oil. Set aside.
Prep the onions – Peel the onions and trim the tops. Using a small knife or melon baller, carefully hollow out the centers, leaving sturdy “shells” for stuffing. Reserve the onion cores for later.
Cook the mushroom mixture – In a skillet, melt butter with minced garlic over medium heat. Add chopped mushrooms and cook until golden brown, about 5 minutes. Remove garlic after cooking if you prefer a milder flavor.
Make the sauce – In another pan, melt the remaining butter and add olive oil, sugar, and balsamic vinegar. Stir well. Add diced tomatoes, cream, salt, and pepper. Simmer until slightly thickened.
Stuff the onions – Fill each onion shell with the meat and rice mixture, packing it in firmly. Arrange them in a baking dish. Pour the creamy tomato sauce around the onions.
First bake – Cover the dish with foil and bake at 180°C (350°F) for 25 minutes.
Add the cheese layer – Mix grated cheese with beaten eggs, a minced garlic clove, and mayonnaise if desired. Remove foil from onions, spoon cheese mixture over each one, and top with thin tomato slices.
Final bake – Return to the oven uncovered and bake for another 20 minutes, until cheese is golden and bubbly.
Serve – Brush the tops with any remaining butter sauce for extra shine and flavor. Serve hot with crusty bread or a fresh salad.

Nutritional Information (per serving, 1 stuffed onion)

Calories: ~280 kcal
Protein: 15 g
Fat: 17 g
Carbohydrates: 18 g
Fiber: 3 g
Sodium: depends on seasoning and cheese choice

Why You’ll Love This Recipe
This casserole is a crowd-pleaser for so many reasons. First, it looks fancy without requiring a complicated technique — hollowing onions is way easier than it sounds. The baked onions turn sweet and mellow, making them perfect vessels for a rich, flavorful filling. The rice inside absorbs the juices from the meat and sauce, giving every bite a perfect balance of texture and taste. Plus, it’s a versatile dish: you can make it ahead, store it easily, and reheat without losing flavor. And honestly, how often do you get to serve something that looks this good straight out of the oven?

The Origins and Inspiration Behind the Dish
Stuffed vegetables have deep roots in many world cuisines — think dolma in the Middle East, stuffed peppers in Mediterranean cooking, or cabbage rolls in Eastern Europe. Onions, however, are a bit of an underdog in the stuffed-veggie world. This dish draws from Eastern European and Mediterranean traditions but gives them a cozy casserole twist, complete with a rich cheese topping. It’s the kind of recipe that feels traditional but still stands out as something new and memorable.

Ingredient Spotlight
Onions – When baked, onions lose their sharpness and develop a gentle sweetness. They’re also a great source of vitamin C and antioxidants.
Ground Meat – Beef, pork, chicken, or turkey all work here. A combination of beef and pork offers the richest flavor.
Rice – Acts as a binder and filler, soaking up the savory juices from the meat and sauce.
Mushrooms – Add earthy depth and a meaty texture without adding actual meat.
Cheese – The gooey, melty topping brings everything together in pure comfort-food fashion.

Storage and Reheating Tips
Leftovers can be stored in an airtight container in the refrigerator for up to 3 days. To reheat, place them in a 180°C (350°F) oven for 10–15 minutes. Avoid microwaving for too long, as it can make the cheese rubbery. You can also freeze the stuffed onions before the final bake — just thaw overnight in the fridge before finishing in the oven.

Common Variations to Try
If you want to mix things up, try using bulgur or quinoa instead of rice for a nutty flavor. For a lighter version, swap the cream for Greek yogurt in the sauce. Vegetarians can replace the meat with lentils and extra mushrooms. You can even play with the cheese — sharp cheddar, fontina, or smoked gouda will each change the flavor profile in a delicious way. For spice lovers, a dash of chili flakes or hot paprika in the filling works wonders.

Pairing Recommendations
Serve this Cheesy Stuffed Onion Casserole with crusty artisan bread to soak up the sauce, or pair it with a crisp green salad to balance the richness. For drinks, a medium-bodied red wine like Merlot or Tempranillo complements the savory depth, while a sparkling water with lemon keeps it refreshing.

Health Benefits
While this recipe leans indulgent thanks to cheese and butter, it still offers nutrition. Onions are packed with antioxidants and compounds linked to heart health. Mushrooms bring B vitamins and immune-boosting properties, and parsley adds a hit of vitamin K and C. You can also make small swaps — like leaner meats, reduced-fat cheese, or whole grains — to create a healthier version without sacrificing flavor.

Conclusion
This Cheesy Stuffed Onion Casserole is proof that onions deserve the spotlight. It’s hearty, flavorful, and surprisingly elegant for something so budget-friendly and easy to make. Whether you’re cooking for a weeknight dinner, a holiday side, or a dinner party centerpiece, this recipe delivers big on taste and presentation. Once you try it, it might just become your new go-to comfort dish — the kind of recipe you’ll find yourself craving again and again.