Pre heat oven to 210c, and line a rimmed baking tray with baking paper and set aside.
Take your pastry sheet out of the freezer to thaw while you prepare the rest of the ingredients.
1 sheet frozen puff pastry
Using a meat mallet (or something else heavy!) lightly pound out the thicker end of each breast, just to make them the same thickness all over.
4 chicken breasts
Place breasts on to the prepared tray, then spread 2 teaspoon of basil pesto onto each breast.
4 tablespoon basil pesto
Place sliced mozzarella on top of the pesto, then roughly spread another 2 teaspoon of basil pesto on top of mozzarella.
125 g fresh mozzarella ball
Place sliced tomato on top of final pesto layer and sprinkle with salt and pepper, then set aside briefly.
1 tomato, salt and pepper
With a sharp knife, divide the sheet of puff pastry into quarters. Then cut each individual quarter into 4 even strips.
Place 4 strips over each chicken breast leaving space between each strip. Tuck the ends of the pastry under the chicken, stretching slightly to fit if needed (watch me make them in the short video above the recipe).
Bake for 20 mins, or until chicken is cooked through.