Preheat the oven to 400.
Sear the sliced sausage in a pan until charred on both sides, about three minutes.
In a small bowl, whisk together the olive oil, juice from half the lemon and a good pinch of salt.
In a 9x13 baking dish, nestle the potatoes, green beans and red onion. Pour the dressing over the veggies and potatoes, then arrange the sausage on top, pushing a few down in the mix here and there. Sprinkle the cheese on top, cover and bake for 30 minutes. Remove the foil and bake another 30 minutes, keeping an eye on the cheese as it will start to brown and bubble.
Serve with the extra lemon wedges and parmesan cheese, if desired! (You should desire.)
Serves 4-6!
