Creamy Baked Onions Asiago

This creamy baked onion dish transforms humble onions into something truly extraordinary. The sweet caramelized onions meld with the rich Asiago cream sauce to create a side dish that often steals the spotlight at my dinner table.

I first made this dish for a holiday gathering when I needed something elegant yet unfussy. The compliments were immediate, and now it's requested at every family dinner where comfort food is the goal.

• Large yellow onions: Their natural sweetness intensifies when roasted and they maintain their shape beautifully
• Olive oil: Use a good quality oil since its flavor will be noticeable
• Fresh thyme: The subtle earthy notes complement the sweet onions perfectly
• Salt and pepper: Freshly ground pepper makes a noticeable difference here
• Heavy cream: Creates the velvety texture that makes this dish irresistible
• Dijon mustard: Adds a tangy depth that balances the richness of the cream
• Asiago cheese: Its nutty complexity elevates the dish beyond a basic cream sauce

Prepare the Onions:

Slice the onions into uniform rounds to ensure even cooking. Keep the slices about ¼-inch thick so they soften properly without falling apart. Arrange them carefully in your baking dish, allowing a slight overlap for the most attractive presentation.

Initial Roasting:

Drizzle the onions generously with olive oil, making sure each slice receives some. Sprinkle with fresh thyme, salt, and pepper. The high temperature of 450°F is crucial here as it begins the caramelization process, developing those complex sweet flavors that make this dish special.

Create the Cream Sauce:

Gently heat the cream just until it begins to simmer, never allowing it to boil which could cause it to break. The Dijon mustard adds a subtle tang that cuts through the richness. When adding the Asiago, stir constantly to ensure a smooth incorporation and prevent any graininess.

Final Baking:

Pour the cream sauce slowly and evenly over the partially roasted onions, ensuring all areas receive some sauce. The foil covering prevents the top from browning too quickly while allowing the onions to fully tenderize. The final result should be bubbling around the edges with a golden top.

My grandmother first introduced me to the magic of baked onions, though her version used Swiss cheese. The moment I tried it with Asiago instead, the dish transformed completely. The nutty intensity of Asiago creates a depth that keeps everyone guessing about your secret ingredient.

Perfect Pairing Suggestions

This creamy onion dish pairs beautifully with simply prepared proteins that allow its complexity to shine. I serve it alongside herb-roasted chicken, grilled steak, or even a festive holiday ham. The rich sauce also makes it an ideal partner for something plain like wild rice or quinoa, which will soak up those delicious flavors.

Make It Your Own

While yellow onions are my standard choice, this recipe welcomes variations. Sweet Vidalia onions create an even more caramelized result, while red onions add a beautiful color contrast and slightly sharper flavor. You can also experiment with cheese options. Gruyère offers a more traditional flavor profile, while a smoked cheese like provolone adds an unexpected depth. For an herb variation, rosemary or sage can replace the thyme for a completely different aromatic experience.

Storage and Reheating

These creamy onions will keep refrigerated for up to three days in an airtight container. When reheating, add a splash of milk or cream to revitalize the sauce which tends to thicken when chilled. Cover with foil and warm in a 325°F oven until heated through, about 15 minutes. I actually think the flavors improve after a day, making this an ideal make-ahead dish for entertaining.

Frequently Asked Questions

→ Can I use a different type of onion?

Yes, yellow onions work best for their sweet flavor, but white onions or even red onions can be used for a slightly different taste profile.

→ What can I substitute for Asiago cheese?

If Asiago is unavailable, Parmesan, Gruyère, or Pecorino Romano are excellent substitutes that still provide a savory, cheesy finish.

→ Can I prepare this dish in advance?

Absolutely. Roast the onions and prepare the cream sauce ahead of time. Assemble just before baking to ensure the cheese melts fresh and evenly.

→ Is this dish suitable for vegetarians?

Yes, as long as the cheese used is vegetarian-friendly (check for non-animal rennet), this dish is a wonderful vegetarian option.

→ How can I make this dish lighter?

Try using half-and-half or milk in place of heavy cream, and reduce the cheese slightly for a lighter version of this dish.

→ What pairs well with creamy baked onions?

This dish complements roasted meats, like beef or chicken, as well as hearty vegetarian dishes like risotto or roasted veggies.