Preheat oven to 425 degrees F / 213 degrees C.
Cut bell peppers lengthwise. Remove stems, ribs and seeds and cut into strips.
Cut zucchinis lengthwise and cut into about 1/4'' / 6 mm thick slices.
Cut onions lengthwise and slice thinly.
On a parchment paper lined baking sheet, toss sausage, bell pepper, zucchini, onion and garlic with a drizzle of olive oil.
Add spices and toss well.
Roast ingredients for about 25-40 minutes depending on desired level of doneness (I like the veggies a bit charred, if possible, so I tend to go for about 35-40 minutes). Flip/stir ingredients every 10 minutes for even cooking.