1. Preheat oven to 400°F. Line baking sheet with parchment paper; set aside.
2. Heat oil in 12-inch nonstick skillet over medium-high heat. Add garlic and shallot; cook and stir 30 seconds. Add spinach; cook and stir 3 minutes or until spinach is wilted. Remove from heat. Stir in pine nuts, salt, red pepper flakes and black pepper. Cool completely.
3. Roll pastry shells out to 5-inch circles on lightly floured board. Place 3 tablespoons spinach mixture onto one half of each pastry. Brush edges of pastry with water. Fold pastry in half, pressing edges with tines of fork dipped in flour to seal. Place empanadillas on prepared baking sheet. Bake 20 minutes or until pastry is puffed and golden. Remove from pan to wire rack. Serve warm.