Wash the tomatoes. Cut mozzarella into 8 slices. Wash basil, pluck leaves. Wash meat, dab dry. Season with salt and pepper.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Cut four rectangular pieces (approx. 20 x 30 cm) of parchment paper to size. Place 2 slices of ham crosswise next to each other on one parchment paper.
Place 1 chicken breast and 2 slices of mozzarella on each. Cover with overlapping ham. Arrange tomatoes and basil on top. Drizzle 1 tablespoon of oil over each.
Fold the paper at the top and sides. Place on a baking tray. Bake in a hot oven for about 25 minutes.