Wash and clean the zucchinis. Peel the garlic. Cut both into slices. Heat the oil in a frying pan, fry the zucchini and garlic slices for about 3 minutes while turning and place in a flat bowl.
Deglaze the roast with vinegar, season to taste with salt, pepper and lemon juice and pour onto the zucchini slices. Add chillies and rosemary sprig. Leave to stand for 30 minutes. Arrange zucchini slices with Bündner Fleisch on plates and serve garnished with a slice of lemon.