Heat oven to 200C/180C fan/gas 6. Tip the potatoes onto a large baking tray. Mix 1 tbsp oil with the paprika, 2 tsp balsamic vinegar and seasoning, then pour over the potatoes and toss together. Bake in the oven for 10 mins while you prepare the chicken.
Mix the peppers with the cheese and seasoning. Open out the chicken thighs and spoon some of the cheese mixture into the centre of each. Pull the sides of the chicken together to seal in the filling, then put each thigh, seam-side-down, on individual squares of foil. Top each thigh with 2-3 overlapping slices of chorizo, then wrap in the foil.
Put the chicken parcels on top of the potatoes and return to the oven for 30 mins until the thighs are cooked and the potatoes are crispy. When the chicken is cooked, mix the remaining 1 tbsp oil and 2 tsp balsamic, and drizzle over the mixed salad leaves. Serve the chicken with the paprika potatoes and salad.