Preheat your oven to 400°F.
Slice the kielbasa sausages into bite-sized pieces.
Chop up the tri-colored peppers and red onion into 1 inch pieces.
Slice the zucchini into bite-sized pieces.
In a large mixing bowl, combine the sliced sausages, peppers, red onion, and zucchini.
Drizzle the mixture with avocado oil and season generously with salt, pepper, and fresh thyme leaves. Toss everything together until well coated.
Transfer the mixture onto a baking sheet lined with parchment paper, spreading it out evenly.
Place the baking sheet in the preheated oven and roast for 25-30 minutes, or until the sausages are golden brown and the vegetables are tender.
Once roasted, remove from the oven and let it cool for a few minutes before serving.