1-First Step: Prep and mise en place Preheat your oven to 400°F. Lightly flour a work surface and thaw 1/2 of a 17.3-ounce package of puff pastry sheets (1 sheet) until flexible but still cool. Thaw 12 cocktail-size frozen fully-cooked beef meatballs (1/2 ounce each) and slice each meatball in half. Measure out 1/2 cup marinara Italian sauce and 1/2 cup shredded mozzarella cheese so everything is ready.

2-Second Step: Roll and cut the pastry Unfold the thawed pastry sheet on the lightly floured surface and roll into a 10 by 15-inch rectangle. Use a sharp knife or a pizza cutter to cut the rectangle into twenty-four 2 1/2-inch squares. Keep flour light to avoid tough pastry.

3-Third Step: Form the tartlet shells Press each pastry square into a mini muffin-pan cup (about 1 3/4 inches across). Pushing gently, shape the pastry so it forms a small cup with sides high enough to hold a meatball half and some sauce. This step gives the puff pastry structure and keeps the filling in place during baking.

4-Fourth Step: Par-bake the shells Bake the prepared mini cups for 15 minutes until they are puffed and golden brown. Par-baking sets the shell so it stays crisp when you add wet sauce and cheese. Watch the pans after 12 minutes to avoid over-browning; ovens vary.

5-Fifth Step: Add the filling After the tart shells are golden, remove the pan from the oven and press one meatball half into each shell. Spoon 1 teaspoon of marinara sauce on top of each meatball half, followed by 1 teaspoon of shredded mozzarella cheese.

6-Final Step: Finish baking and serve Return the pan to the oven and bake for an additional 5 minutes or until the cheese melts. Let the tartlets cool a few minutes in the pan before removing. Serve warm for best taste.