Rustic French Onion Tart: A Savory Delight with Rich, Caramelized Onions and Flaky Pastry

The **Rustic French Onion Tart** is a charming, hearty dish that speaks to the soul of traditional French cuisine. Born from the flavorful heartlands of France, this savory tart is a celebration of humble ingredients elevated to gourmet status. Its origins are deeply rooted in the Alsace region, where onions are a staple, and straightforward cooking methods transform them into something magical.

Picture a golden, flaky pastry base supporting a blanket of deeply caramelized onions, their natural sweetness enhanced by a touch of balsamic vinegar and thyme. As the tart bakes, your kitchen fills with the comforting, aromatic promise of a satisfying meal. Perfect for brunches, casual lunches, or as a standout appetizer at dinner parties, this tart pairs beautifully with a crisp white wine or a light, fruity red.

### Ingredients:- Pastry: - 1 and 1/4 cups all-purpose flour - 1/2 cup unsalted butter, chilled and diced - 1/4 teaspoon salt - 1/4 cup ice cold water

- Filling: - 4 large onions, thinly sliced - 2 tablespoons olive oil - 2 teaspoons balsamic vinegar - 1 teaspoon fresh thyme leaves - Salt and pepper to taste - 1 cup Gruyère cheese, grated - 1 egg, beaten (for egg wash)

### Instructions:

1. **Prepare the Pastry:** - In a large mixing bowl, combine the flour and salt. Add the butter pieces, rubbing them into the flour with your fingertips until the mixture resembles breadcrumbs. - Gradually add the ice-cold water, mixing until the dough starts to come together. Form the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 30 minutes.

2. **Cook the Onions:** - Heat olive oil in a large skillet over medium-low heat. Add the sliced onions and a pinch of salt. - Cook, stirring occasionally, until the onions become soft and start to caramelize, about 25-30 minutes. - Stir in the balsamic vinegar and thyme, cooking for another 5 minutes. Remove from heat and let cool.

3. **Assemble the Tart:** - Preheat your oven to 400°F (200°C). - Roll out the chilled dough on a floured surface into a circle about 12 inches in diameter. Transfer it to a parchment-lined baking sheet. - Spread the caramelized onions evenly over the pastry, leaving a 2-inch border around the edges. - Sprinkle the grated Gruyère cheese over the onions. - Fold the edges of the pastry over the filling, creating a rustic border.

4. **Bake the Tart:** - Brush the beaten egg over the folded edges of the pastry. - Bake in the preheated oven for 30-35 minutes, or until the pastry is golden and the cheese is bubbly and melted.

5. **Serve and Enjoy:** - Allow the tart to cool slightly before slicing. Serve warm or at room temperature, garnished with a sprinkle of fresh thyme.

### Cooking Tips and Serving Suggestions:- For a twist, add a handful of cooked bacon or pancetta to the onion mixture before baking.- This tart pairs perfectly with a light, crisp green salad dressed simply with lemon and olive oil.- A glass of chilled Pinot Gris or a fruity Beaujolais complements the flavors beautifully.

This **Rustic French Onion Tart** is a kitchen staple that captures the essence of French culinary artistry, providing comfort and sophistication in each bite. Whether you're hosting a gathering or enjoying a quiet meal, this dish invites you to savor the simple pleasures of taste and tradition.