Caramelized Onion and Gruyere Tart

By AislePrompt Test Kitchen · Reviewed by AislePrompt Editorial · ·

A savory tart with deeply sweet caramelized onions and nutty Gruyere cheese baked in a flaky crust. This french-inspired vegetarian ready in about 80 minutes layers all-purpose flour, cubed cold butter, ice water into a dessert worth slowing down for — great for weekend baking, holiday tables, or any time you want a sweet payoff at the end of a meal. Each serving lands at about 290 calories and feeds 8, so it slots into a weekend bake or a special-occasion dessert tray. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

★ 3.1 (11 ratings) Prep: 45 min Cook: 35 min Serves 8 French cuisine 290 cal/serving
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Ingredients

Instructions

  1. Step 1: Make crust: Pulse flour and 1/4 tsp salt in a food processor. Add cold butter and pulse until crumbly. Add ice water and pulse until dough forms. Chill 30 minutes.
  2. Step 2: Roll dough into a 12-inch circle. Fit into a 9-inch tart pan, trimming edges. Prick bottom with fork. Chill 15 minutes.
  3. Step 3: Sauté onions in 2 tbsp butter over medium-low heat for 30 minutes until deeply golden. Stir in brown sugar and thyme, cook 2 more minutes.
  4. Step 4: Preheat oven to 375°F (190°C). Spread onions evenly over crust. Sprinkle with gruyere cheese. Whisk cream, salt, and pepper, then pour over cheese.
  5. Step 5: Bake for 30-35 minutes until golden and bubbly. Cool 15 minutes before slicing.

Equipment for this recipe

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Frequently asked questions

How long does Caramelized Onion and Gruyere Tart take to make?

Total time is about 80 minutes (45 min prep + 35 min cook). Most home bakers find this fits a weekend afternoon; chill or store as the recipe directs before serving.

How do I store leftover Caramelized Onion and Gruyere Tart?

Cool fully before storing. Most baked desserts keep at room temperature in an airtight container for 2–3 days, or in the fridge for up to 5 days. Cream- or custard-based desserts must go in the fridge within 2 hours; reheat gently or serve cold per the recipe.

Can I substitute ingredients in Caramelized Onion and Gruyere Tart?

Yes — most ingredients in this recipe have flexible swaps. For oil, use any neutral high-smoke-point oil (avocado, grapeseed, refined coconut). For aromatics, dried herbs at ⅓ the volume of fresh work in a pinch. The full ingredient list is shoppable on Instacart so you can see substitutes in real time.

How do I scale Caramelized Onion and Gruyere Tart for a different number of people?

The recipe is written for 8 servings. Multiply each ingredient by (your serving target / 8). Cook time stays roughly the same up to 2x; for 3-4x batches, switch from a skillet to a sheet pan or stockpot so the food isn't crowded — overcrowding steams instead of browns.

What goes well with Caramelized Onion and Gruyere Tart?

French vegetarian like this pair well with a simple grain (rice, couscous, or crusty bread), a quick salad with acid (lemon vinaigrette, pickled onions), and a pan sauce or yogurt-based dip. Tap "Plan a meal with the AI" to get specific side suggestions.

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