Heat oil in a large skillet over medium-high heat. Cook sausages, turning to brown all sides, 4 to 5 minutes.
Place browned sausage in slow cooker. Add the peppers, onions, garlic, and Ragu(R) Old World Style(R) Traditional Pasta Sauce to the slow cooker; stir. Turn to low and cook for 6 to 8 hours.
Serve over slices of hearty fresh bread; garnish with fresh basil.