For the vegetable casserole with mashed potatoes, cook the chopped vegetables (e.g. carrots, green beans, cauliflower) in boiling water for about 5 minutes and place in a greased gratin dish.
Cut the ham into strips and spread evenly over the vegetables. Whisk egg with a little milk and spices and pour over the top. At the end, pour the finished mashed potatoes into the gratin dish and sprinkle grated cheese on top.
Cook the vegetable casserole with mashed potatoes in the oven for about 20 minutes.