Elevate canned spinach: Gruyère & Artichoke Tartlets!

Ingredients

• 1 1/4 cups (150g) all-purpose flour, plus more for dusting
• 1/2 teaspoon (2g) salt
• 1/2 cup (1 stick/113g) unsalted butter, very cold and cubed
• 1/4 cup (60ml) ice water
• 2 tablespoons (30ml) olive oil
• 1 small yellow onion, finely chopped (about 1/2 cup)
• 2 cloves garlic, minced
• 2 (13.5 ounce) cans canned spinach, well-drained and squeezed dry
• 1 (14 ounce) can artichoke hearts, drained and quartered
• 1/2 cup (120ml) heavy cream
• 1/4 cup (60ml) grated Parmesan cheese
• 1/2 cup (50g) grated Gruyère cheese, plus more for topping
• 1 large egg, lightly beaten
• 1 tablespoon lemon zest
• 1/4 teaspoon grated nutmeg
• Salt and freshly ground black pepper to taste
• 1 large egg, beaten (for egg wash)