Preheat the oven to 400°F (200°C). Finish slicing the peeled potatoes and prepare the pepper and onion wedges.

Heat 2 teaspoons olive oil in a large skillet over medium heat. Add the Italian sausage pieces. Turn occasionally and brown for about 5–10 minutes. Move the sausage into a large baking dish.

Add the separate 1/4 cup olive oil to the skillet. Add the potato slices and cook for about 10 minutes, turning occasionally, until browned. Use batches if necessary so the slices can brown.

Transfer the potatoes to the baking dish, leaving some oil in the skillet.

Add the green peppers, red peppers and onions to the skillet. Stir and cook for about 5 minutes, until beginning to soften.

Add these vegetables to the sausage and potatoes.

Pour over the white wine and chicken stock. Add the Italian seasoning, salt and pepper, then gently combine.

Bake uncovered for about 20–25 minutes, until hot and bubbling and the potatoes are tender. Check doneness with a thermometer before serving: fresh pork sausage needs at least 160°F (71°C); the finished casserole should reach 165°F (74°C) in the center. Continue cooking if needed.