Preheat the oven to 180 degrees C.
Slice the potatoes into pieces 1.5cm thick (no need to peel). Lay the pieces over the bottom of a large oven proof casserole dish.
Put the chicken on top of the potatoes. Insert a bulb of garlic into the cavity.
Cut the lemon in half and tuck down the side of the chicken. Lay the anchovy fillets over the top of the chicken. Sprinkle over the capers. Add a pinch of salt and pepper. Drizzle over the olive oil.
Put the casserole dish (uncovered) in the oven. Cook for 1 hour and 40 minutes, checking often to ensure that the chicken skin isn’t burning (if it colours too much, top with foil).
When the chicken is cooked, remove it from the oven. Take the chicken out of the casserole dish and place on a plate. Cover with foil.
Roughly chop the peppers. If your tomatoes are large, cut them in half. Put the vegetables in the dish on top of the potatoes. Return to the oven for 30 minutes.
When you are ready to serve, carve the chicken and serve a portion with the potatoes, peppers and tomatoes.