Slice the veggies: Cut bell peppers into strips and slice the onion. Mince garlic and set aside.
Brown the sausage: Heat 1 tablespoon of olive oil in a large skillet over medium heat.
Add sausage links and cook 3–4 minutes per side until well browned. Remove to a plate; they will finish cooking later.
Sauté peppers and onions: Add the remaining oil to the same pan. Toss in peppers and onion with a pinch of salt.
Cook 6–8 minutes, stirring occasionally, until softened with some caramelized edges.
Add garlic and spices: Stir in garlic, oregano, basil, smoked paprika, and red pepper flakes. Cook 30–60 seconds until fragrant.
Return sausage and simmer: Slice browned sausages into 1-inch pieces and add back to the skillet. Reduce heat to medium-low and cook 5–7 more minutes, stirring, until sausage is cooked through and veggies are tender.
Brighten and season: Drizzle in red wine vinegar, toss, and taste.
Add more salt, pepper, or vinegar as needed. Finish with chopped parsley.
Serve: Enjoy as is, or plate over cauliflower rice or zucchini noodles. Sprinkle with Parmesan if you like.