In a large saute pan, heat 1/4-cup olive oil over high heat until smoking. Add the calamari, sliced garlic, and chile flakes, and cook for 1 minute, until the calamari is tender. Remove and set aside.
In a large skillet, heat the remaining oil until smoking. Add the peppers and cook until they are soft and browned, turning occasionally to cook evenly. Once they are soft, remove and drain on paper towels.
Remove most of the oil from the pan and add the tomatoes, chopped garlic, reserved calamari, and salt and pepper, to taste. Cook over high heat for 5 minutes, then remove from heat, and stuff the mixture into the peppers. Top with parsley and serve.