I myself love this didsh and have had it at Bertucci's many times. I have also wondered what the recipe is and have made an abridged version of the one above that is more similar to the Bertucci's descripsion. Here it is.

TORTELLINI GRATINATI

8 oz. cheese filled tortellini (cooked)
4 oz. chicken breast (cooked & diced)
3 oz. cream
2 oz. Ricotta cheese
2 oz. shredded mozzarella
2 oz. Romano
1 oz. parmigiano (parmesan cheese)
2 oz. Alfredo sauce
3 oz. diced plum tomatoes

Place tortellini in an oven proof casserole dish. Add chicken. Ladle sauces over tortellini cover with cheeses.

Bake in oven at 350 degrees F for 15-20 minutes until bubbling.