Step-by-Step Instructions:

Step 1: Prepare the Tartlet Shells

1. 1. Preheat the Oven: Preheat your oven to 375°F (190°C).

1. 1. Thaw the Puff Pastry: If using frozen puff pastry, let it thaw at room temperature for about 20-30 minutes or until it’s pliable but still cold.

1. 1. Roll Out the Pastry: Lightly flour your work surface and roll out the puff pastry sheet to smooth any creases. Aim for a thickness of about 1/8 inch.

1. 1. Cut the Pastry: Use a round cookie cutter or a glass to cut the pastry into circles slightly larger than your tartlet molds. Alternatively, you can cut the pastry into squares if using square molds.

1. 1. Line the Molds: Gently press the pastry circles into the tartlet molds, ensuring the pastry fits snugly against the sides. Trim any excess pastry hanging over the edges.

1. 1. Prick the Bases: Use a fork to prick the bottom of each pastry shell. This prevents the pastry from puffing up too much during baking.

1. 1. Optional Egg Wash: Beat the egg in a small bowl and brush the edges of the pastry shells lightly with the egg wash. This will give them a golden, shiny finish.

1. 1. Pre-Bake the Shells: Place the tartlet molds on a baking sheet and bake in the preheated oven for 8-10 minutes, or until the shells are lightly golden. Remove from the oven and set aside to cool slightly.

Step 2: Prepare the Filling

1. 1. Sauté the Garlic: Heat 1 tablespoon of olive oil in a pan over medium heat. Add the minced garlic and sauté for 1-2 minutes until fragrant. Be careful not to burn the garlic.

1. 1. Cook the Spinach: Add the chopped spinach to the pan and cook for 2-3 minutes, stirring occasionally, until the spinach is wilted and any excess moisture has evaporated. Season with salt, pepper, and nutmeg (if using). Remove from heat and let cool slightly.

1. 1. Mix the Filling: In a mixing bowl, combine the sautéed spinach, crumbled feta cheese, shredded cheese, and heavy cream or milk. Stir until everything is well combined. The mixture should be creamy but not too runny.

Step 3: Assemble the Tartlets

1. 1. Fill the Shells: Spoon the spinach and cheese mixture evenly into the pre-baked tartlet shells. Fill each shell almost to the top, leaving a little space for the tomatoes.

1. 1. Add the Tomatoes: Place a few pieces of cherry tomato on top of each tartlet. You can press them lightly into the filling so they stay in place.

Step 4: Bake the Tartlets

1. 1. Bake: Place the filled tartlets on a baking sheet and bake in the preheated oven for 12-15 minutes, or until the filling is bubbly and the edges of the pastry are golden brown.

1. 1. Cool Slightly: Remove the tartlets from the oven and let them cool in the molds for 5 minutes. This makes them easier to remove.

Step 5: Serve

1. 1. Remove from Molds: Gently remove the tartlets from the molds and place them on a serving platter.

1. 1. Garnish (Optional): You can garnish with a sprinkle of fresh herbs like parsley or basil for added flavor and color.

1. 1. Serve Warm: These tartlets are best served warm as an appetizer, snack, or light meal.

For perfect tartlets, follow some baking tips. You want a golden-brown crust and a fully cooked filling. Bake for 15-20 minutes, watching closely to avoid burning. You'll get about 15 appetizer-sized or 10 main course-sized triangles.

After baking, let the tartlets cool a bit before serving. They're great warm or at room temperature, especially with a Greek yogurt dip. Tip: You can store them in the fridge for up to three days or freeze for a week.