Preheat the oven to 425°F, and line a baking sheet with aluminum foil.
Place chopped peppers and onion on the prepared baking sheet.
Drizzle veggies with olive oil and sprinkle with italian seasoning, basil, and salt. Use your hands to mix it all together and spread in an even layer on the baking sheet.
Place the sausages on top of the veggies.
Bake in preheated oven for 25–30 minutes or until veggies are soft and the sausages are cooked through.