Slice the bell peppers and onions into strips, then mince the garlic.
Heat the olive oil in a large skillet over medium-high heat.
Add the whole sausage links and cook until browned on all sides.
Transfer the sausages to a cutting board and allow them to rest for 1 minute.
Slice each sausage link into thick pieces.
Add the sliced peppers and onions to the skillet, using the flavorful drippings left behind.
Cook for 10 minutes, stirring occasionally, until the vegetables are softened and caramelized.
Stir in the minced garlic and crushed tomatoes or tomato sauce, then cook for 1 minute until fragrant.
Return the sliced sausages to the skillet and cook for another 5 minutes, until the sausages are cooked through and all the ingredients are well combined.
