Healthy Caramelized Onion & Gruyere Tart
This tart features sweet, slow-caramelized onions, creamy Tuscan cheese, and a crisp whole-wheat crust. We lighten it up by using Greek yogurt in the filling and a thinner layer of cheese without sacrificing flavor. It works beautifully as a light lunch, brunch centerpiece, or elegant appetizer.
⏳ Time
Prep: 20 minutes
Cook: 45 minutes
Total:1 hour 5 minutes
Ingredients
For the Crust
1 cup whole wheat flour
½ cup all-purpose flour
1tbp of olive oil
½ tsp salt
3–4 tbsp ice water
(Or use store-bought whole wheat puff pastry for speed.)
For the Filling
2 large yellow onions, thinly sliced
1 tbsp olive oil
½ tsp salt
1 tsp balsamic vinegar (optional, for depth)
1 large egg
½ cup Greek yogurt (plain, 2% or whole)
½ cup milk (low-fat or whole)
¾ cup Gruyeres cheese, shredded
Freshly ground black pepper, to taste
Fresh thyme leaves (optional, for garnish)
ℹ️ Instructions
1. Make the Crust
1. In a bowl, mix whole wheat flour, all-purpose flour, and salt.
2. Cut in the cold butter using a pastry cutter or fingers until mixture resembles coarse crumbs.
3. Gradually add ice water, mixing until dough just comes together.
4. Shape into a disk, wrap, and chill for at least 30 minutes.
2. Caramelize the Onions
1. Heat olive oil and butter in a large skillet over medium heat.
2. Add onions and salt, stirring occasionally.
3. Cook 25–30 minutes, lowering heat if they brown too quickly, until golden and sweet.
4. Stir in balsamic vinegar (if using) during the last 2 minutes. Remove from heat and let cool slightly.
3. Prepare the Tart Shell
1. Preheat oven to 375°F (190°C).
2. Roll out dough on a floured surface to fit a 9-inch tart pan.
3. Press into the pan, trim edges, and prick bottom with a fork.
4. Blind bake for 12 minutes using parchment and pie weights. Remove weights and bake 3 more minutes.
4. Make the Filling
1. In a bowl, whisk together egg, Greek yogurt, milk, and a pinch of pepper.
2. Stir in half of the shredded Gruyere.
5. Assemble & Bake
1. Spread caramelized onions evenly in the tart shell.
2. Pour egg-yogurt mixture over the top.
3. Sprinkle with remaining Gruyere.
4. Bake for 25–30 minutes, until set and lightly golden.
6. Serve
Cool slightly before slicing. Garnish with fresh thyme if desired.
Notes & Tips
Even lighter option: Use a phyllo crust with olive oil brushing instead of pastry.
Flavor twist: Add sautéed mushrooms or roasted red peppers to the onion layer.
Make ahead: Caramelize onions a day in advance and refrigerate.
⁉️ Frequently asked questions FAQ
Q: Can I freeze the tart?
Yes — cool completely, wrap well, and freeze for up to 2 months. Reheat at 350°F until warmed through.
Q: Can I make it crustless?
Yes, pour the filling into a greased pie dish and bake as a frittata-style tart.
✅ Nutritional Information
Calories: ~230
Protein: 8g
Carbs: 20g
Fat: 12g
Fiber: 3g
Sugar: 4g