Core the peppers, cut them in half, and cut them into 1/8 inch thick slices In a large saute pan, heat 2 tablespoons of the olive oil over medium high heat. When the oil is hot, add the peppers. Cook them for 2 minutes without stirring. Stir them well and cook them for 2 more minutes without stirring. Repeat this procedure 2 or 3 times until peppers start to brown and wilt. Add the garlic and saute the mixture for 2 minutes. With a slotted spoon, transfer the peppers to a large bowl. Add the remaining 2 tablespoons olive oil to the pan. When the oil is hot, add the onions. Saute them for about 3 minutes or until they are lightly browned. Return the peppers to the pan. Add the tomatoes, fresh and dried oregano, and the bay leaf. Season the sauce to taste with salt and pepper. Reduce the heat to medium and cook the sauce partially covered, stirring occasionally , for 10 to 13 minutes until the peppers have softened completely. Prepare a charcoal or gas grill so that one side of the coals or heating elements is medium hot and the other side has a low heat; first lightly spray the grilling rack with vegetable spray to prevent sticking; or preheat broiler. Lightly brush the sausage with olive oil. Grill it on high heat for 2 to 3 minutes or until it is browned. Turn it over and grill the other side for 2 to 3 minutes or until it is browned. Transfer it to the lower heat and grill it for 7 to 8 minutes. Check for doneness by cutting into the sausage. Return it to high heat and grill it for about 1 minute on each side to complete the cooking. Spread the pepperonata on a large platter. Lay the sausage ring on top. Serve with crusty bread.