Peel, wash and slice the carrots and potatoes. Cook in boiling salted water for about 12 minutes. Add peas about 3 minutes before the end of cooking time. Pour into a sieve and drain.
Meanwhile, put 500 ml of lukewarm water into a pot, stir in the sauce powder with a whisk, bring to the boil and boil for 1 minute. Remove from the stove. Add potatoes, carrots and peas to the sauce, put them into one large or two smaller greased casserole dishes.
Sprinkle with cheese and bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 25 minutes. In the meantime quarter the ham slice. Cut each quarter into 3 strips of as equal a size as possible and place them on a shish kebab skewer at small intervals to create four sails.
Remove the casserole from the oven and place the ham sails inside.