Lightly pound each chicken breast between 2 pieces of plastic wrap.

In a glass or porcelain dish, combine the lemon juice with 1 tablespoon of olive oil, and 1 teaspoon of garlic. Season with salt and pepper to taste.

Place the chicken in the marinade. Cover and refrigerate for no more than 2 hours.

To make the sauce, heat 1 tablespoon of olive oil in a 2-quart saucepan over medium heat. Add the onion and the remaining teaspoon of garlic. Cook, stirring, over low heat for 5 minutes or until the onion is tender. Add the cream and bring to a boil. Then add the sage and 1/4 cup parsley. Remove from the heat and set aside.

To make the rigatoni, bring 3 quarts of salted water to a boil in a stock pot. Boil the rigatoni for about 12 minutes, or according to the package directions. Drain and set aside.

Meanwhile, remove the chicken from the marinade and pat dry. Dip the chicken lightly in the seasoned flour on both sides.

Heat the remaining 2 tablespoons of olive oil in a 12-inch skillet over medium heat. Cook the chicken for about 5 minutes per side or until completely cooked through. Transfer the chicken to a plate and loosely cover with foil to keep warm.

Add the white wine to the skillet and boil, stirring with a wooden spoon, until there are only 2 tablespoons of liquid in the pan. Add the reserved sauce and bring to a boil. Add the Gorgonzola and Parmesan cheeses and simmer. Remove from the heat and season with salt and pepper to taste.

To assemble the dish, toss the pasta with sauce until well coated. Divide the pasta between 4 dishes, top each portion with chicken, and garnish with parsley. Serve immediately.