Caramelized Onion Baked Brie with Thyme and Walnuts

Caramelized onion baked brie is a warm, savory appetizer for cooks who want something deeper than a jam topping. The onions get a full 30 minutes on low heat, which is the only way they go sweet instead of sharp. A splash of balsamic vinegar turns them into a thick onion jam, and a hot, softened wheel of brie takes it from there. The recipe serves 6 and takes 55 minutes in total, but most of that is the onions, which need a stir every few minutes and little else. Prep is 10 minutes and the oven time is 15. It is the right pick for a party where you want the work finished the day before.

Why this works

• Onions only caramelize after their water leaves. Rushing the heat browns the sugar and skips the sweetness.
• Butter and olive oil together give flavor and a higher tolerance for heat than butter alone.
• Balsamic vinegar goes in at the end and cooks off until the pan is dry, so the onions hold their shape on a spoon.
• The jam goes on the hot wheel, so the cheese loosens under it and the two mix as you scoop.
• Walnuts and fresh thyme add crunch and an herbal note against the rich cheese.

What to know about the ingredients

Onions. Two medium yellow onions, thinly sliced, give about 300 g. Slice them evenly so they cook at the same rate. Yellow onions are best here, since they have enough sugar to brown deeply.

Fats. One tablespoon each of unsalted butter and olive oil. The pan should be wide, so the onions spread out and lose their water faster.

Balsamic vinegar. Only 2 teaspoons. A basic bottle is fine. It adds a dark, sweet tang and helps the jam set.

The brie. A double cream wheel, 8 oz and about 5 in across. Choose one that is ripe but not runny.

Walnuts and thyme. Walnut halves bring crunch, and fresh thyme leaves keep the topping from tasting too sweet. Fine salt goes into the onions early to help draw out their water.

Caramelized Onion Baked Brie

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The onions get a full 30 minutes on low, which is the only way they go sweet instead of sharp.

Prep10 min

Cook15 min

Total55 min

Serves6

Ingredients

• Brie wheel, double cream — 8 oz wheel (225 g)
• Yellow onions, thinly sliced — 2 medium (300 g)
• Unsalted butter — 1 tablespoon (14 g)
• Olive oil — 1 tablespoon (15 g)
• Balsamic vinegar — 2 teaspoons (10 g)
• Fresh thyme leaves — 1 teaspoon (2 g)
• Walnut halves — ⅓ cup (40 g)
• Fine salt — ½ teaspoon (2 g)

Instructions

1. Melt the butter with the olive oil in a wide skillet over medium low heat until the foam dies down, about 1 minute.
2. Add the onions and the salt and cook, stirring every 5 minutes, until they collapse to about a third of their volume and turn deep amber, 30 to 35 minutes. Lower the heat if they darken at the edges before the middle softens.
3. Stir in the balsamic vinegar and cook until the pan is dry again and the onions hold their shape on a spoon, 1 to 2 minutes. This is the onion jam.
4. Heat the oven to 350 F (175 C) and score the top rind in a crosshatch of 1 in (2.5 cm) squares, about 3 mm deep, until the paler paste shows in the cuts.
5. Bake the wheel in a snug dish 12 to 15 minutes, until the center gives under one finger.
6. Pile the onion jam on the hot wheel until the top is covered, scatter the walnut halves over it, add the thyme, and serve while the cheese is still loose.

Notes

• Bake at 350 F (175 C) for 12 to 15 minutes. Wheel size: 225 g / 8 oz wheel, 5 in across.

Nutrition per serving

231Calories

9 gProtein

6 gCarbs

19 gFat

Estimated per serving from standard nutrition reference values; will vary with brands and substitutions.

Tips for getting it right

1. Melt the fats first. Heat the butter and olive oil over medium low until the foam dies down, about 1 minute.
2. Stir every 5 minutes. Add the onions and salt and cook until they collapse to about a third of their volume and turn deep amber, 30 to 35 minutes.
3. Watch the edges. If they darken before the middle softens, lower the heat.
4. Finish with balsamic. Cook until the pan is dry again and the onions hold their shape on a spoon, 1 to 2 minutes. That is your onion jam.
5. Score and bake. Cut a crosshatch of 1 in (2.5 cm) squares, about 3 mm deep, then bake the wheel in a snug dish at 350 F (175 C) for 12 to 15 minutes, until the center gives under one finger.
6. Pile on hot. Cover the top with the onion jam, scatter the walnut halves and thyme over it, and serve while the cheese is still loose.

How to store, freeze and make ahead

The onion jam is the make-ahead part. It keeps 5 days in the fridge and freezes 3 months, so make it the day before a party and reheat it gently while the wheel bakes. If you freeze it, thaw it in the fridge first. Bake the brie fresh, since the loose, warm center is the point of the dish. If any cheese is left, cover and refrigerate it, then rewarm it before serving.

What to serve with it

Grilled sourdough and cornichons are the pairings that suit it best. The char on the bread and the sharp pickle cut through the sweet, rich topping. Crisp apple slices, sturdy crackers and a few extra walnuts also work well. For a drink, a dry red or a crisp white pairs nicely with the savory onions.

Variations

• Extra herbs. Add a little minced fresh rosemary alongside the thyme.
• Pecans. Use pecan halves in place of the walnuts.
• Smoky note. Lay a few thin slices of prosciutto on the board beside the wheel.
• Sweet and savory. Drizzle a little honey over the onions just before serving.

For more warm appetizers, browse our guide to Baked Brie and Cheese Boards. The Fig Jam and Prosciutto Baked Brie and the Garlic Herb Baked Brie are good companions.