Peel and wash the potatoes and cut them into cubes of about 1.5 cm. Cover and precook in salted water for about 5 minutes. Drain and let drain.
Peel the carrots, wash them, quarter them lengthwise and cut them into very small pieces. Clean and wash the celery stalks and cut them into thin slices. Peel onions and garlic and chop finely. Wash the rosemary, shake dry, pluck off the needles and chop.
Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Heat 2 tablespoons of oil in a large pan. Fry the minced meat in it until coarsely crumbly. Add carrots, celery, onions, garlic and rosemary and fry briefly.
Season with salt and pepper. Stir in the tomato paste, sweat briefly. Add cherry tomatoes, bring to the boil. Season to taste with salt and pepper.
Oil the casserole dish. Fill the mince mixture into the dish and spread potato cubes on top. Sprinkle with 3 tablespoons of oil. Bake in a hot oven for 25-30 minutes until the potatoes are golden brown.