Heat the 1 tbsp olive oil in a large, deep Skillet over medium-high heat. Add the 1 lb Italian sausage mild or hot, casings removed, breaking it up with a Wooden Spoon, and cook until browned and cooked through, about 6–8 minutes. Use a Slotted Spoon to transfer the 1 lb Italian sausage mild or hot, casings removed to a plate, leaving the drippings in the pan.

Reduce the heat to medium. Add the diced 1 medium yellow onion finely diced to the same Skillet and cook, stirring occasionally, until softened and translucent, about 4–5 minutes. Add the 4 cloves garlic minced and cook for 1 minute more until fragrant. Stir in the 2 tbsp tomato paste and cook for another minute, letting it caramelize slightly.

Add the diced 1 can diced tomatoes undrained (with their juices), 3 cups chicken broth low-sodium, dried 1 tsp dried oregano, ½ tsp smoked paprika, ¼ tsp red pepper flakes (if using), ½ tsp kosher salt plus more, and ¼ tsp black pepper freshly ground. Stir to combine and bring to a gentle boil. Return the browned 1 lb Italian sausage mild or hot, casings removed to the pan.

Stir in the dry 1 ½ cups orzo pasta dry. Reduce the heat to medium-low, cover the Skillet, and simmer, stirring every 2–3 minutes to prevent sticking, until the 1 ½ cups orzo pasta dry is tender and has absorbed most of the liquid, about 12–15 minutes. If it looks too thick before the 1 ½ cups orzo pasta dry is done, add a splash of 3 cups chicken broth low-sodium or water.

Taste and adjust seasoning with ½ tsp kosher salt plus more and ¼ tsp black pepper freshly ground. Serve directly from the Skillet, topped with freshly grated ¼ cup Parmesan cheese freshly grated and chopped 2 tbsp fresh flat-leaf parsley chopped.