Roasted Parmesan Creamed Onions

Roasted Parmesan creamed onions are one of those unexpected side dishes that steal the spotlight. I take tender, caramelized onions and bake them in a rich, creamy Parmesan sauce until bubbly and golden. It’s a comforting, elegant dish that works just as well for holidays as it does for a cozy weeknight dinner.

Why You’ll Love This Recipe

I love this recipe because it transforms humble onions into something truly indulgent. The roasting brings out their natural sweetness, and when I pair that with a creamy Parmesan sauce, every bite feels like comfort food with a gourmet twist. It’s rich without being too heavy, and it pairs beautifully with everything from roast chicken to grilled steak or a holiday ham.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

• Yellow or white onions (small to medium size, peeled and halved)

• Olive oil or melted butter

• Salt

• Black pepper

• Heavy cream

• Garlic (minced or grated)

• Fresh thyme or rosemary (optional)

• Grated Parmesan cheese

• Optional: breadcrumbs or extra cheese for topping

Directions

1. I start by preheating the oven to 375°F (190°C) and greasing a medium-sized baking dish.

2. I peel the onions, slice them in half from root to tip, and trim the ends slightly to keep them together.

3. I arrange the onions cut-side down in a baking dish, drizzle them with olive oil or melted butter, and season with salt and pepper.

4. I roast them uncovered for about 30–35 minutes, or until they start to caramelize and soften.

5. While the onions are roasting, I heat the cream in a small saucepan with garlic, thyme, and a pinch of salt and pepper. I let it simmer gently for a few minutes, then stir in the Parmesan cheese until smooth and slightly thickened.

6. I pour the cream sauce over the roasted onions, sprinkle a little extra Parmesan (or breadcrumbs) on top, and return the dish to the oven.

7. I bake for another 15–20 minutes, until the sauce is bubbly and the top is golden brown.

8. I let it cool slightly before serving, so the sauce can thicken a bit more.

Servings and timing

This recipe makes about 4–6 servings as a side dish.
Prep time: 10 minutes
Cook time: 50–55 minutes
Total time: 1 hour

Variations

Sometimes I add a splash of white wine to the cream sauce for extra depth. I’ve also stirred in a bit of Dijon mustard or used Gruyère instead of Parmesan for a slightly different flavor. If I want a crunchier top, I mix breadcrumbs with Parmesan and broil for the last 2–3 minutes. For a shortcut, I use pre-cooked pearl onions instead of roasting whole onions from scratch.

Storage/reheating

I store leftovers in an airtight container in the fridge for up to 3 days. To reheat, I bake them in a 350°F oven until warmed through, or use the microwave in short bursts. The sauce may thicken, so I sometimes add a splash of cream when reheating to loosen it up.

FAQs

Can I use pearl onions instead of whole onions?

Yes, I’ve used frozen or fresh pearl onions when I want to save time. Just make sure they’re fully cooked before adding the cream sauce.

What type of onion works best?

I usually go for yellow or white onions—they roast beautifully and have a nice balance of sweetness and bite.

Can I make this ahead of time?

Definitely. I prepare and assemble everything, then refrigerate before the final bake. When ready to serve, I bake it until hot and bubbly.

Can I make this dish vegetarian?

Yes, just make sure the Parmesan cheese is labeled vegetarian (some versions use animal rennet). The rest of the ingredients are already vegetarian-friendly.

Is this dish keto-friendly?

It is! Since there’s no flour or starchy base, this recipe fits well into low-carb or keto diets—especially if I skip the breadcrumb topping.

Conclusion

Roasted Parmesan creamed onions are a simple yet luxurious side dish that adds something special to any meal. I love the sweet, roasted flavor of the onions paired with the creamy, cheesy sauce—it’s rich, satisfying, and so easy to make. Whether I’m serving guests or just craving something a little extra, this dish never disappoints.