tuna bake The very best recipes are timeless. Tuna Bake has been around for eons and for good reason: it's easy, it's tasty and it's budget friendly. Serves 6 200g penne 425g tin tuna 1 onion 2 sticks celery 1 carrot 60g butter 3 tbs plain flour 400ml milk 1 tsp mustard powder 1 cup grated cheese salt and pepper