Preheat the Oven: Preheat your oven to 400°F (200°C).

Prepare the Pan: Line a large, heavy-duty baking sheet with tin foil. Spray the foil lightly with non-stick cooking spray and set it aside.

Prep the Sausage & Veggies: Cut the smoked turkey sausage into thick, uniform rounds (about 1/2-inch thick). Chop the onion into large chunks or wedges.

Prep the Potatoes: Wash the baby red and golden potatoes thoroughly and pat them completely dry with a paper towel. Slice them in half, or quarter them if they are particularly large, ensuring they are roughly the same size as the sausage rounds.

Season the Ingredients: Place the prepared sausage, onions, and potatoes into a large mixing bowl. Drizzle the olive oil over the top. Add the sea salt, black pepper, smoked paprika, and Cajun spice. Use your hands or a large spatula to toss everything together until every piece is evenly coated.

Arrange for Roasting: Spread the seasoned mixture onto the prepared baking sheet. Ensure the ingredients are in a single, uncrowded layer so they roast rather than steam. Use two baking sheets if necessary.

Roast to Perfection: Roast in the preheated oven for 25 to 30 minutes. Halfway through the cooking time, carefully remove the pan and use a spatula to flip the ingredients. Return to the oven until the potatoes are fork-tender and the sausage has browned, crispy edges.

Serve: Remove from the oven and let cool slightly before serving. Enjoy immediately!