Heat olive oil in a large pan and fry onion for 6 minutes until golden.
Stir in chilli flakes, kidney beans, tomatoes, wine, and garlic.
Boil the mixture and simmer for 20 minutes.
Heat a griddle pan until it is very hot.
Brush steaks with olive oil and season with black pepper.
Sear steaks for 3 minutes on each side for medium rare.
Drizzle steaks with chilli oil and rest before slicing diagonally.
Stir the chopped chocolate into the bean chilli.
Divide shredded lettuce across four plates.
Place steak slices on lettuce and spoon hot chilli to the side.
Top with sour cream and serve with guacamole and warm tortillas.