Warm up the milk. Crumble the yeast and dissolve in it. Mix flour, soft fat in pieces, 1 egg and about 1/2 teaspoon salt. Add yeast milk and knead everything smooth. Cover and leave to rise in a warm place for about 40 minutes
Peel and halve the onion and cut into fine slices. Clean, wash and cut the spring onions into rings. Peel, wash and roughly grate the carrots. Thyme wash, pluck. Chop nuts, except 4-5 halves
Heat the oil. Fry the onion until transparent. Add spring onions, carrots and thyme and fry. Fold in chopped nuts and season everything
Knead the dough again and roll out round (approx. 32 cm) on a little flour. Place in a greased tart or springform pan (approx. 26 cm Ø), pressing up 2-3 cm at the edges. Covered we
Wash the apple, remove the core (e.g. with an apple corer) and cut into thin rings or slices. Mix 4 eggs and sour cream and season
Spread the onion mixture on the dough. Place the apple on top and sprinkle the remaining nuts over it. Pour a sand cast over it. Bake the tart in a preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for 45-50 minutes