You’re Probably Not Making Melting Onions, But Should

Not much beats a piping hot bowl of French onion soup, especially when it’s freezing cold outside. Its rich, savory and slightly sweet broth can warm the coldest bones, while the cheesy bread topping makes every bite irresistible. But making it from scratch can be a serious time commitment. That’s why, when I’m short on time and craving those classic flavors, I turn to one of my absolute favorite ways to cook onions: French Onion Soup–Style Melting Onions.

Why You Should Make French Onion Soup–Style Melting Onions

Onions are often the unsung heroes of the kitchen, quietly adding depth as aromatics or flavor enhancers. They’re also nutritional powerhouses, offering anti-inflammatory and antioxidant properties thanks to a compound known as quercetin, which may help support heart health.

As great as this sounds, onions may cause problems for some people (myself included). They contain fructans, a type of complex carbohydrate that can trigger digestive discomfort. Fortunately, digestive enzymes let me still enjoy them in my favorite recipes. Plus, cooking onions slowly—like in this recipe—can help break down some of these compounds, making them easier to enjoy.

When I cook with onions, I love letting them shine as the star: rich, sweet and caramelized—just like in French Onion Soup–Style Melting Onions.

The recipe calls for cutting sweet onions in 1-inch thick slices, laying them on a large rimmed baking sheet and brushing both sides with a mixture of oil, melted butter, fresh thyme, salt and pepper. Roast the onions at 450°F until lightly browned, flipping them halfway through for even cooking. This takes about 30 minutes, which is plenty of time to work on the flavorful toasted breadcrumbs.

The topping starts by mixing together panko breadcrumbs with melted butter and fresh thyme, then toasting the mixture in a skillet until golden brown. Set the toasted breadcrumbs aside and turn your attention back to the onions.

Once the onions are lightly browned, flip them once more and pour in some beef broth and a splash of sherry vinegar. Put the pan back into the oven and roast until the broth reduces slightly and the onions are ultra-soft—which takes about 10 more minutes.

To get the classic cheesy French onion soup topping, sprinkle the onions with Gruyère and mozzarella, then broil on high until the cheese is bubbly—watch closely, it happens fast. When ready, top with the toasted panko and a few sprigs of fresh thyme.

The result? A side dish or appetizer that captures all the flavor of French onion soup in every bite.

Other “Melting” Recipes

These French Onion Soup–Style Melting Onions may be inspired by the classic soup, but the technique actually comes from melting potatoes. The technique is pretty much the same: bake the potatoes in a metal baking pan until mostly tender, then pour in some broth and bake until the liquid is mostly absorbed and the vegetables are super creamy. This “melting” technique works with more than just potatoes—here are some of my favorite variations:

• Melting Beets with Goat Cheese. Beets are one of my all-time favorite veggies, and I especially love when they are roasted. The edges get crispy, while the insides are super tender. Topping them with crumbled goat cheese makes an elegant dish that’s surprisingly easy to pull together.
• Melting Cabbage. Cabbage is practically a flavor sponge, making it perfect for the melting technique. Warm spices like cumin and caraway go incredibly well with tender cabbage, but variations like Garlic-Parmesan Melting Cabbage and Marry Me Melting Cabbage are equally delicious.
• Melting Sweet Potatoes with Maple Butter. As a Vermonter, I put maple syrup on just about everything. Sweet potatoes happen to go perfectly with maple, which is why this recipe for Melting Sweet Potatoes works so well. The thick slices of sweet potatoes are roasted, then soak up a sweet-tangy sauce made from broth, maple syrup and a splash of lemon.
• Melting Butternut Squash with Cumin & Cilantro. Winter squash works beautifully for the melting technique as the edges caramelize lightly while the inside becomes almost creamy. The flavor profile is inspired by chermoula, a North African condiment, and features paprika, cumin and cilantro.
• Melting Broccoli. Like cabbage, broccoli is one of the best veggies for melting as it soaks up the flavors from broth very well. This recipe packs on the umami with the addition of miso and a kick of heat from chili crisp.

Our Expert Take

Onions are key to many dishes, but they often play a supporting role as a flavor enhancer. One of the best ways to prepare them lets onions step into the spotlight: French Onion Soup–Style Melting Onions. This method, inspired by classic French onion soup and the technique for melting potatoes, yields rich, tender slices of onion finished with tangy beef broth and topped with bubbly cheese and crispy breadcrumbs. Give onions a chance to play a starring role and you’ll be rewarded with an incredibly rich, cheesy side dish.