Caramelized Onion and Gruyère Flatbread with Thyme

By AislePrompt Editorial · Published 2026-07-07 · Updated 2026-07-07

Crispy flatbread topped with sweet caramelized onions, melted Gruyère cheese, and fragrant fresh thyme leaves. This French-inspired vegetarian recipe, ready in about 45 minutes, pairs prepared flatbread, yellow onion, unsalted butter for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 350 calories and feeds 4, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. 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.

Ingredients

• 1 large (10-inch) prepared flatbread
• 2 medium, thinly sliced yellow onion
• 2 tbsp unsalted butter
• 1 tbsp olive oil
• 1/2 tsp salt
• 1/4 tsp black pepper
• 1 cup shredded Gruyère cheese
• 1 tbsp fresh thyme leaves

The pizza stone or steel we’d bake this on → Best Pizza Stones and Steels for 2026: Top Picks + Buying Guide

Instructions

1. Step 1: Heat 2 tbsp unsalted butter and 1 tbsp olive oil in a large skillet over medium-low heat. Add 2 thinly sliced medium yellow onions, 1/2 tsp salt, and 1/4 tsp black pepper. Cook slowly, stirring occasionally for 25 minutes until onions are deeply golden and caramelized.
2. Step 2: Preheat oven to 425°F. Place the prepared 10-inch flatbread on a baking sheet.
3. Step 3: Spread the caramelized onions evenly over the flatbread, then sprinkle 1 cup shredded Gruyère cheese evenly on top.
4. Step 4: Bake in the oven for 10-12 minutes until the cheese melts and the edges of the flatbread become crispy and golden.
5. Step 5: Remove from oven and scatter 1 tbsp fresh thyme leaves over the flatbread. Slice and serve warm.