Caramelized Onion and Gruyère French Flatbread

By AislePrompt Editorial · Published 2026-05-29 · Updated 2026-05-29

A golden flatbread topped with sweet caramelized onions and melted Gruyère cheese for a savory, crowd-pleasing appetizer. This French-inspired quick recipe (vegetarian), ready in about 85 minutes, pairs all-purpose flour, warm water, active dry yeast for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 320 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

• 2 cups all-purpose flour
• 3/4 cup warm water
• 1 tsp active dry yeast
• 2 tbsp olive oil
• 1 tsp salt
• 2 medium, thinly sliced yellow onion
• 2 tbsp unsalted butter
• 1 cup shredded Gruyère cheese
• 1 tsp fresh thyme leaves
• 1/2 tsp freshly ground black pepper

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: In a small bowl, dissolve 1 tsp active dry yeast in 3/4 cup warm water (110°F) and let sit for 5 minutes until frothy.
2. Step 2: In a large bowl, combine 2 cups all-purpose flour and 1 tsp salt. Add the yeast mixture and 1 tbsp olive oil, stirring until a dough forms. Knead on a floured surface for 6-8 minutes until smooth and elastic.
3. Step 3: Place the dough in a lightly oiled bowl, cover with a damp towel, and let rise in a warm place for 45 minutes until doubled.
4. Step 4: While the dough rises, melt 2 tbsp unsalted butter in a skillet over medium heat. Add 2 thinly sliced yellow onions and cook slowly, stirring occasionally, for 20-25 minutes until deeply golden and caramelized.
5. Step 5: Preheat oven to 450°F and line a baking sheet with parchment paper.
6. Step 6: Punch down the dough and roll into a 12x8-inch rectangle on a floured surface. Transfer to the baking sheet and brush with remaining 1 tbsp olive oil.
7. Step 7: Spread the caramelized onions evenly over the dough, then sprinkle 1 cup shredded Gruyère cheese and 1 tsp fresh thyme leaves on top. Season with 1/2 tsp freshly ground black pepper.
8. Step 8: Bake for 12-15 minutes until the cheese is bubbly and the edges of the flatbread are golden and crisp.
9. Step 9: Let cool for 5 minutes, slice, and serve warm.