Slice the vegetables and sausage as noted in the ingredients list. Preheat the oven to 400°F (205°C).
Place garlic powder, salt, Italian seasoning blend, and black pepper in a separate small bowl and stir to combine. Set aside.
Add the potatoes, green beans, onion, and sausage to a large bowl.
Pour the olive oil over the top of the sausage and vegetables.
Sprinkle the spices over the sausage, green beans, onions and potatoes. Stir until the spices are evenly distributed.
Place the sausage and vegetables in a single layer on a baking sheet lined with parchment paper.
Bake at 400°F (205°C) for 30-40 minutes, stirring halfway through, until the potatoes are tender and the vegetables are browned.
Sprinkle with fresh parsley before serving.