Wash the potatoes and cook with the skin in boiling water for 10-15 minutes. Meanwhile wash the meat, dab dry and cut into strips. Clean mushrooms, wash if necessary and cut larger mushrooms in half.
Peel the shallots and cut into slices. Quarter the peppers, clean, wash and cut into fine cubes. Cut cucumbers into slices. Drain potatoes, rinse with cold water, peel and halve.
Heat the oil in a pan and fry the meat in it vigorously. Add shallots, mushrooms and potatoes and fry briefly. Season with salt and pepper and deglaze with broth. Stir in mustard and let it braise for about 5 minutes.
Fold in paprika and cucumber and warm up. Garnish with parsley.