Marinade yellow boletuses in hot water for 30 minutes, then strain them and serve water. Chop finely onions and garlic. Cut peeled carotts, celery and red peppers into fine stripes. Halve or quarter mushrooms. Heat 2 tbsp. oil and braise lightly onions and garlic. Add nutmeg and coriander, deglaze with soja sauce and boil down. Add 150 ml water from yellow boletuses marinade. Fold in strained tomatoes, beefstock, mushrooms and bay leaf. Let all simmer for about 15 minutes, then season to taste with sherry, salt and pepper.
Heat 2 tbsp. oil in a pan and fry carotts, celery and red peppers for about 4 minutes. Spice with salt. Add mushrooms and fry for 3 minutes more. Cover and let all simer for 5 minutes. Serve sauce with vegetable.