Preheat the oven to 400°F (204°C). Line a large sheet pan with parchment paper.
Dice the baby potatoes into small, even pieces for faster cooking.
Trim and halve the green beans, cut the broccoli into florets, chop the bell peppers into 1-inch pieces, and slice the beef smoked sausage into thick rounds.
Spread the potatoes, green beans, broccoli, peppers, and sausage evenly across the prepared sheet pan.
Drizzle with olive oil and sprinkle with paprika, garlic powder, oregano, parsley, red pepper flakes (if using), salt, and black pepper.
Toss everything together until evenly coated, then spread into a single layer without overcrowding the pan.
Bake for 15 minutes.
Remove the pan, stir the vegetables and sausage, then return to the oven for another 10–15 minutes, or until the vegetables are crisp-tender and lightly browned.
If desired, sprinkle with freshly grated Parmesan cheese while hot and garnish with chopped parsley.
Serve the Sheet Pan Sausage and Veggies over cooked rice or quinoa, or enjoy it on its own.