Preheat your oven to 400°F (200°C). Slice the smoked sausage into rounds, halve the baby potatoes, and trim the green beans. Place them in a large mixing bowl.
Add sliced onions and minced garlic to the bowl. Drizzle with olive oil and sprinkle Italian seasoning, salt, black pepper, and smoked paprika. Toss everything together until well coated.
Spread the sausage, potatoes, and green beans evenly in a greased baking dish. Ensure the ingredients are in a single layer for even roasting.
Cover with foil and bake for 30 minutes. Remove the foil, stir the ingredients, and bake uncovered for another 15–20 minutes until the potatoes are tender and slightly crispy.