This dish uses half a recipe of Fresh Pasta. You may double the filling and freeze the extra ravioli, or roll out the extra dough and make fettuccine, which is easily dried and stored.
Heat a skillet over medium heat; add oil. Add shallots; cook until translucent, about 4 minutes. Add peas; cook until soft, about 8 minutes. Remove from heat; stir in ricotta, chervil, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Mash with a fork.
Divide dough into two pieces. Using a pasta machine, roll one piece of dough through widest opening, brushing very lightly with flour. Fold dough into thirds; pass through machine again, folded side up. Repeat process three more times, or until dough is smooth.
Roll dough through remaining settings on the machine (widest to narrowest), using as little additional flour as possible, until very thin. Place sheet on a lightly floured surface; cut in half lengthwise. Cover half with plastic wrap. With remaining half, place scant teaspoons of filling 1 inch apart in two rows. Moisten pasta around each mound of filling, using a pastry brush dipped in water. Top with remaining half sheet of pasta; press around filling to seal. Use a pastry wheel to cut into squares. Brush with a dry brush to eliminate excess flour. Place ravioli on a tray generously dusted with semolina. Repeat with remaining dough and filling. Chill until ready to cook.
Bring a large pot of salted water to a boil. Cook ravioli about 2 minutes, until tender but al dente. Divide among plates.
Place butter in a saute pan over medium heat; cook until lightly browned, 6 to 8 minutes. Pour over ravioli; top with shaved Parmesan, chervil, salt, and pepper. Serve.