Cook shells in salted boiling water for 8–10 minutes until al dente, then drain and rinse under cool water.

Heat olive oil in a skillet over medium heat. Add minced garlic and cook for 30 seconds until fragrant, then toss in mixed vegetables and sauté until tender-crisp (about 5 minutes).

In a bowl, whisk ricotta, egg, half the mozzarella, salt, and pepper until smooth and creamy.

Fold sautéed vegetables into the cheese mixture until evenly distributed.

Grease a mini muffin tin, then spoon filling into each shell standing upright, filling generously.

Preheat oven to 375°F, bake cups for 12–15 minutes. Sprinkle remaining mozzarella and Parmesan on top halfway through.