Heat 1 tbsp butter in large frying pan. Sauté shallots and mushrooms for around 3 minutes. Season to taste with salt and pepper. Add fresh cream, wine, lemon zest, parsley, capers and Gruyère AOP. Let simmer for 5 minutes then set aside. Fry chicken breast for 2 minutes on each side. Season with salt and pepper and keep warm.
Heat tortillas according to package instructions. Top with mushrooms in cream sauce, chicken, Vacherin Fribourgeois AOP and lettuce.
Cover using a second tortilla, toast 2 minutes on each side in a non-stick frying pan, then serve.