To make the filling, heat 1 Tbs. olive oil in a large skillet over medium-low. Add 1 onion, finely chopped, 1 green bell pepper, cut into 1/2-in. pieces, and a pinch of kosher salt, and cook, stirring occasionally, until softened, 5 to 7 minutes. Add 2 garlic cloves, minced, and 1 lb. sweet Italian sausages, casings removed, breaking up with a wooden spoon. Cook over medium-high heat, stirring regularly, until sausage starts to turn golden brown. Remove from heat and add 1 tsp. paprika, then transfer to a bowl to cool. Once cool, fold in 1 cup coarsely grated extra-sharp cheddar (or crumbled queso fresco). Preheat oven to 375°F and line two large baking sheets with parchment paper. Using 28 store-bought empanada wrappers, spoon 2 Tbs. filling onto one side of the wrapper. Fold wrapper over the filling and crimp with a fork to seal. Repeat with the remaining wrappers and filling, placing the empanadas on the prepared baking sheets. Bake until golden brown, 25 to 30 minutes. Frozen, cooked empanadas can be added directly to lunch boxes in the morning and will be ready to eat at midday.