Place all of the ingredients into a food processor and blitz.
Marinate the lamb in all but 2 tbsp of the mixture, cover and refrigerate for at least 2 hours but preferably overnight.
Slice the peppers, onion and mushrooms ready for stir frying.
Salsa
Meanwhile make the salsa. Mix the ingredients together.
Crème fraîche and cucumber dip
Mix the ingredients together and season with salt and pepper.
Cook the fajita filling
Remove the lamb from the fridge and pan fry for 6-8 minutes on a medium to high heat. Check the meat is cooked to your liking (if a little pink then add back to the pan) and rest for 10 minutes, wrapping it in foil to keep warm.
Meanwhile add the vegetables to a wok with a little oil. Pour over the remaining marinade and stir fry for 5-6 minutes or until soft.
Heat the tortillas to the packet instructions.
Lay the cooked vegetables in a large serving dish and place the lamb in a line on top. Spoon on the cooking liquid and sprinkle with coriander leaves.
Serve with guacamole and refried beans.