# Ingredient List:
→ Pastry
01 - 1 sheet (about 8.8 oz) store-bought or homemade shortcrust pastry
→ Filling
02 - 7 oz smoked bacon, diced
03 - 3 large yellow onions, thinly sliced
04 - 2 tablespoons unsalted butter
05 - 1 tablespoon olive oil
06 - 1 teaspoon sugar
07 - 1/2 teaspoon salt
08 - 1/4 teaspoon black pepper
09 - 1/4 teaspoon dried thyme
→ Custard
10 - 3 large eggs
11 - 3/4 cup heavy cream
12 - 1/3 cup whole milk
13 - 1/4 teaspoon ground nutmeg
14 - 2.8 oz grated Gruyère or Swiss cheese
15 - Salt and pepper to taste
# Step-by-Step Instructions:
01 - Preheat oven to 350°F. Roll out the pastry and line a 9-inch tart pan. Trim excess pastry and prick the base with a fork. Chill while preparing the filling.
02 - In a large skillet over medium heat, cook the bacon until crisp. Remove with a slotted spoon, drain on paper towels, and set aside.
03 - Discard excess bacon fat, leaving about 1 tablespoon. Add butter and olive oil to the pan. Add onions, sugar, salt, and thyme. Cook over medium-low heat, stirring occasionally, for 25-30 minutes until onions are deeply golden and caramelized. Remove from heat and let cool slightly.
04 - In a bowl, whisk together eggs, cream, milk, nutmeg, and a pinch of salt and pepper.
05 - Scatter the caramelized onions and bacon evenly over the chilled pastry base. Sprinkle with grated Gruyère. Pour the custard mixture gently over the filling.
06 - Bake for 35-40 minutes, or until the quiche is set and lightly golden. Let cool 10 minutes before slicing.
07 - Serve warm or at room temperature.