Get your oven ready by preheating it to 400°F (about 200°C).
While the oven heats, pop your diced butternut squash into a microwave-safe bowl. Microwave it for just 2 minutes – this helps it cook perfectly with the other veggies later. It should be tender, but not fully cooked through. Use this time to chop your other ingredients!
In a large mixing bowl, combine the rest of your prepared veggies (bell pepper, zucchini, red onion) and the sliced kielbasa sausage. Add the partially cooked butternut squash.
Drizzle the olive oil over the veggies and sausage. Then, sprinkle on the dried thyme, smoked paprika, garlic salt, and ground black pepper.
Give everything a good toss until every piece is beautifully coated in the oil and spices – this ensures maximum flavor!
For easy cleanup, you can line your baking sheet with parchment paper or aluminum foil, though it's not strictly necessary.
Lightly brush a large baking sheet with a little olive oil, then spread your seasoned sausage and veggies in a single layer.
Bake for about 25 minutes, or until the vegetables are tender, slightly browned, and the sausage is perfectly cooked.