Cook and drain the shells according to package directions.

Drizzle 3 Tbsp. of the olive oil on the bottom of a medium-sized pot so that it forms a thin coating on the bottom. Heat the pot over medium heat and add the onion and 6 cloves of garlic. Stir to coat the onions and garlic in oil and allow them to soften and sizzle, 3-4 minutes. Add the sweet peppers and stir to combine. Saute an additional 3-4 minutes. Lower the heat and add the tomato puree, dried basil, dried oregano, dried parsley, sugar, 2 tsp. of salt and 1 tsp. of pepper. Cover and simmer on low heat, stirring occasionally.

Puree the fresh basil, 2 cloves of garlic, parmesan cheese, olive oil, pine nuts, 1 tsp. salt and 1/8 tsp. pepper in a blender until smooth. Transfer to a bowl and stir in the ricotta cheese, 1 cup grated mozzarella and egg. Stir to combine.

Preheat oven to 375 degrees. Spoon about 2 tsp. of the ricotta mixture into each cooked pasta shell. Ladle out enough tomato gravy to coat the bottom of a 9x13 inch baking dish. Arrange the shells in rows in the baking dish. Cover with more gravy and the remaining mozzarella cheese. Bake 40 minutes.