In Mexican cooking, it is not uncommon for coffee to be used in a number of savoury dishes. For this burger, the meat patty is mixed with Mexican spices and the patty is then coated with freshly ground coffee to add a rich, smoky flavour to the meat when cooked. It matches well with the creamy avocado and spicy salsa.
To make the coffee rub, mix all ingredients in small bowl.
To make the patties, mix all ingredients together in a large bowl. Roll mix into four evenly sized balls and flatten into a patty shape. Keep in the fridge until ready to cook.
Heat a barbecue or frypan to medium heat. Sprinkle 1 tsp of the coffee rub on top side of each burger. Place patties, rub side down, on the pan or barbecue. Cook for about 5 minutes on each side or until they form a nice dark crust. Remove from pan when they are cooked and rest for 5 minutes.
Place a patty on each bun and add all or any of the toppings you like.