Heat 1 tablespoon of 2 tbsp olive oil divided in a Skillet over medium-high heat. Add the 1 ¼ lb Italian sausage links sweet or hot, sliced into 1-inch rounds rounds in a single layer and cook, undisturbed, for 2–3 minutes per side until deeply browned. Transfer to a plate and set aside.

Reduce heat to medium and add the remaining 1 tablespoon of 2 tbsp olive oil divided to the same Skillet. Add the sliced 1 large yellow onion halved and sliced into half-moons and all the 1 whole red bell pepper seeded and sliced into strips, 1 whole green bell pepper seeded and sliced into strips, and 1 whole yellow bell pepper seeded and sliced into strips. Season with ½ tsp kosher salt plus more and ¼ tsp black pepper freshly ground. Cook, stirring occasionally, for 6–8 minutes until the vegetables are softened and beginning to caramelize at the edges.

Add the 4 cloves garlic minced, 2 tbsp tomato paste, 1 tsp smoked paprika, and ½ tsp dried oregano to the Skillet. Stir everything together and cook for 1–2 minutes until the 2 tbsp tomato paste darkens slightly and the 4 cloves garlic minced is fragrant.

Pour in the 1 can diced tomatoes undrained (with their juices) and ½ cup chicken broth low sodium. Stir to combine, scraping up any browned bits from the bottom of the pan. Nestle the browned 1 ¼ lb Italian sausage links sweet or hot, sliced into 1-inch rounds back into the Skillet.

Bring the mixture to a gentle simmer, then reduce heat to medium-low. Cook uncovered for 12–15 minutes, stirring occasionally, until the sauce has thickened slightly and the 1 ¼ lb Italian sausage links sweet or hot, sliced into 1-inch rounds is cooked through (160°F internal). Taste and adjust seasoning with ½ tsp kosher salt plus more and ¼ tsp black pepper freshly ground.

Remove from heat and scatter fresh 2 tbsp fresh flat-leaf parsley roughly chopped over the top. Serve straight from the Skillet with crusty bread, hoagie rolls, or over rice or polenta.