Serves 8 to 10

For the sauce :
3 tablespoons olive oil
1 medium onion, chopped
3 garlic cloves, minced
2 (28 ounce) cans Italian tomatoes in juice, drained, reserving juice, and finely chopped
1/2 cup water
1 teaspoon sugar
1 teaspoon salt
1/4 cup chopped fresh basil

For the filling:
2 pounds fresh ricotta (3 cups)
2 large eggs
1 ounce finely grated Parmigiano-Reggiano (1/2 cup)
1/3 cup chopped fresh parsley
1/2 teaspoon salt
1/2 teaspoon black pepper

20 to 30 manicotti shells, parboiled
1 pound fresh mozzarella

Preheat oven to 400 degrees F.

For the sauce:
Heat oil in a 5- to 6-quart stock pot over moderately high heat until hot but not smoking, then sauté onion, stirring occasionally, until golden, about 4 minutes. Add garlic and sauté, stirring, until golden, about 1 minute. Add tomatoes with juice, water, sugar, and salt and simmer, uncovered, stirring occasionally, until thickened, about 30 minutes. Stir in basil and remove from heat. Season to taste with salt and pepper.

For the filling:
Stir together all ingredients and set aside.

Assemble the manicotti:
Spread 1 cup of sauce in the bottom of two 9-by-12-inch baking dishes. Fill the manicotti shells with the filling and place in the baking dishes on top of the sauce. Top the manicotti with the remaining sauce and the mozzarella slices.

Bake 15 minutes, covered, until sauce is bubbly. Remove cover and bake 5 more minutes, until cheese is browned.