For the fajitas, cut the beef fillet into narrow strips, marinate with lime juice, tequila and curaçao and leave to marinate for about 1 hour.
Heat some oil in a pan and quickly fry the marinated beef in it. Season with salt and pepper. Lift out and keep warm.
Warm the tortillas briefly in a coated pan or in the microwave, if desired. Place tortillas on top, spread with sour cream and top with chopped tomatoes.
Place the beef strips on top. Pour guacamole and salsa on top and roll up tortillas.