Asiago Creamy Baked Onions

This creamy baked onion dish brings together the sweetness of roasted onions with the savory richness of Asiago cheese and cream. It is the perfect side when you want something out of the ordinary yet deeply comforting. I reach for this recipe every time I need a showstopper that still feels totally homey.

I first brought this to a friend's potluck and watched it disappear before anything else. The nutty cheese melts beautifully into the sauce for a flavor that always gets recipe requests.

Ingredients

• Large yellow onions: The right kind gives a mellow sweetness and keeps their shape as they roast. When choosing onions pick ones that feel heavy and have dry skins.
• Olive oil: Adds richness and helps encourage caramelization. Use extra virgin for better flavor.
• Fresh thyme: Brings an herby aroma that pairs especially well with the cheese. Use just the leaves not the stems and look for bright green sprigs.
• Salt and pepper: Brings everything together. Use kosher salt and freshly cracked black pepper if you can.
• Heavy cream: Forms the backbone of the sauce. Go for the highest fat content available for the most decadent result.
• Dijon mustard: Lends subtle tang and cuts through the richness. Use a smooth high-quality Dijon.
• Asiago cheese: Gives the dish a nutty salty kick and big melt factor. Buy a wedge and grate it fresh for best melting and taste.

Instructions

Prepare the Onions:

Lay out your peeled and sliced onions in a single even layer in a greased baking dish. This ensures even roasting. You want each slice snug but not overlapping so each round gets caramelized edges.

Season and Roast:

Drizzle onions with olive oil and scatter over the chopped thyme salt and pepper. Slide the dish into a 450 degree oven and roast for twenty minutes. Check that the onions soften and some edges are golden. This step builds a rich sweet base.

Make the Creamy Sauce:

While the onions roast set a saucepan over medium heat and pour in the heavy cream. Slowly bring it to a simmer to avoid scorching. Whisk in the Dijon mustard and half the grated Asiago stirring until the cheese is melted and the sauce is smooth and glossy. Let it gently bubble for a minute.

Assemble and Bake:

Carefully pour the hot cream sauce over the roasted onions making sure each slice gets some love. Sprinkle the rest of the Asiago cheese on top. Cover snugly with foil and bake another twenty minutes until everything is tender and bubbling.

Uncover and Finish:

If you want a lightly golden cheesy crust take off the foil and broil the dish for two to three minutes. Watch closely so the cheese does not burn. Serve hot for the ultimate cheesy indulgence.

Asiago is my favorite part here because the flavor is just unbeatable. I can still remember my grandma sprinkling big shreds of Asiago all over Sunday casseroles and that scent makes this instantly nostalgic for me. The first bite brings back family-style dinners from my childhood.

Storage Tips

Once cooled store leftovers in an airtight container in the fridge. This dish keeps well for up to three days. Reheat in a low oven or microwave gently to keep the sauce smooth and the onions tender. If you want to plan ahead the whole dish can be assembled a day early and baked right before serving.

Ingredient Substitutions

You can swap the Asiago for Gruyere or even sharp provolone. If you are out of heavy cream half and half works but will result in a lighter sauce. Sweet onions like Vidalia will give a milder taste but yellow onions hold up best in the oven.

Serving Suggestions

This makes a lovely side for roast chicken pork or even holiday beef. Paired with crusty bread and a green salad it can be a cozy vegetarian entrée. Sometimes I serve it alongside grilled sausages and it never fails to impress.

Cultural Context

Creamy baked onions feel like a cross between French gratin and classic Sunday casseroles. I heard stories of French cooks finishing onion dishes with a pour of cream and cheese especially in chilly weather. This recipe takes those comforts and bakes them into a simple American style side that feels right at any table.

Seasonal Adaptations

In spring swap the thyme for fresh chives or tarragon. Add roasted cherry tomatoes in summer for extra sweetness. In fall tuck thinly sliced apples in with the onions for a cozy twist.

Helpful Notes

Always slice onions evenly so they cook in sync. Use room temperature cream for the smoothest sauce. Let the dish sit five minutes after baking so the flavors settle.

Success Stories

The first time I took this to my book club someone said they would have eaten it for dessert. Another time my brother in law who hates onions cleaned his plate. Friends often ask for the recipe and come back telling me they added their own twists.

Freezer Meal Conversion

You can assemble the dish completely up to the last bake cover with foil and freeze it. Thaw fully in the fridge and then bake as usual. It makes a great prep ahead holiday side. Individual portions also freeze well for lunches in the weeks ahead.

Serve this dish hot and watch it vanish fast. It brings cozy flavor and elegance to any meal.

Recipe FAQs

→ Can I use a different type of onion?

Yes, sweet or white onions can be used, but yellow onions offer a rich, savory flavor ideal for baking.

→ What can I substitute for Asiago cheese?

Pecorino Romano or Parmesan are great substitutes if Asiago isn't available, offering similar sharpness.

→ How can I make this dish lighter?

Use light cream or half-and-half instead of heavy cream, and reduce cheese to suit your preference.

→ Can I prepare this ahead of time?

You can assemble the dish in advance and bake just before serving for maximum freshness and texture.

→ What meals go well with this dish?

This creamy onion bake pairs excellently with roasted meats, grilled chicken, or a leafy green salad.