Bring a large pot of water to the boil for the pasta.
Add salt and the shells and boil for 6 minutes.
Add the broccoli to the pasta and boil an additional 2 to 3 minutes until the pasta is al dente and the broccoli is crisp-tender.
Drain well and return the pasta and broccoli to the cooking pot.Meanwhile, heat the butter in a large skillet and cook the onion and red pepper-over medium-low heat for 5 minutes until they are just softened.
Stir in the flour and cook, stirring, for 1 minute.
Stir in the cream, milk and wine and bring just to the boil, stirring constantly.
Stir in the ricotta and remove the skillet from the heat.
Stir in the cheddar and 1/3 cup of the Parmesan until the cheeses are melted and well blended.
Add the sauce and the chicken to the pasta and broccoli and mix gently.
Spoon the pasta mixture into a buttered 9-by-13-inch pan.
Combine the bread crumbs with the remaining Parmesan and sprinkle the mixture evenly over the casserole.
Heat the oven to 350 degrees.Bake for 20 to 25 minutes until the casserole is heated through and the bread crumbs are golden.