Preheat the oven to 400 degrees F.

Heat a medium pot over high heat and bring 1 to 2 inches of water to a boil. Add the quahogs and cover the pan. Steam them until they open, at least 6 minutes. Discard any quahogs that do not open. Strain broth and reserve 1/4 cup. Remove the quahogs from the shells (leaving the shells intact; do not snap apart) and chop the meat.

In a large skillet, heat the oil and butter over medium-high heat. Add the chourico, onions, and green pepper and cook until the vegetables soften, about 5 to 7 minutes. Add the chopped clam meat, lemon juice, and hot sauce and cook for 2 to 3 minutes more.

In a large mixing bowl, pour the chourico mixture over the cubed bread and add the cilantro, parsley, red pepper paste, bread crumbs and clam broth. Mix gently, and then stuff the each clam shell with about 3/4 cup of clam stuffing. Wrap the clam shells in aluminum foil and bake until heated through, about 15 minutes. Serve immediately.