To prepare the piadina with sausage and roasted peppers, begin with the peppers. Wash the bell peppers, place them in a baking dish, and drizzle with a little olive oil. Roast in a preheated conventional oven at 200°C (400°F) for 40 minutes. Once roasted, remove from the oven, cover the baking dish tightly with plastic wrap, and let cool completely.
Slice the red onion thinly and set aside.
Score the sausage with a small pairing knife and remove the casing.
Pour a drizzle of olive oil into a skillet, add the sliced onion, and cook gently until softened.
Add the sausage meat, crumbling it with a wooden spoon as it cooks.
Brown for a few moments, then add the sweet paprika and deglaze with the white wine.
Season with a pinch of salt and cook for a few more minutes until the sausage is well-browned and cooked through.
Meanwhile, peel the cooled bell peppers, remove the seeds and membranes, slice them into strips, and toss with salt and olive oil.
Warm the piadinas in a dry skillet or griddle for 1–2 minutes, flipping at least once.
Transfer the warm piadinas to a board and arrange a portion of roasted peppers and cooked sausage over one half of each flatbread.