Cook the Lumache in salt water until al dente, rinse and set aside.
Mix the breadcrumbs, milk and 3 tablespoons of oil in a blender. Then add the spinach and ricotta and puree until smooth. Season to taste with nutmeg, salt and pepper.
Heat the tomatoes with the remaining oil and the crushed garlic and season again with salt and pepper. Here everyone can season as they please. I add a pinch of oregano. Now place on the bottom of the baking dish.
Fill the Lumache with the spinach mixture using a teaspoon and place on the tomato sauce. Cover and bake in the oven at 180 degrees for 20 minutes.