Cook pasta shells in salted boiling water until al dente, then drain and cool.
Mix ricotta, mozzarella, Parmesan, egg, parsley, salt, and pepper in a bowl until smooth.
Heat olive oil in a saucepan, sauté garlic for 1 minute, then add beet puree and crushed tomatoes. Simmer for 10 minutes, season, and stir in balsamic vinegar.
Spread a thin layer of sauce in the bottom of a 9×13-inch baking dish.
Stuff each shell with the ricotta mixture, arrange in the dish, some twisted for effect.
Pour remaining sauce over shells, some dripping onto edges.
Bake uncovered for 25–30 minutes until bubbly.
Drizzle with black garlic oil or balsamic glaze, let sit 10 minutes before serving.
Notes
Nutrition Information (per serving): Calories: 350 Total Carbs: 45g Net Carbs: 40g Fats: 15g Protein: 18g