2) Form 4 big patties from the meat and bean mixture then heat 15ml of oil in a large frying pan over medium-high heat.
3) Cook patties for 7 to 8 mins on each side.
4) While the burgers cook, combine avocado with garlic, lime zest and juice, jalapeno and red onion. Mash to roughly combine, then stir in the sour cream.
5) To serve, place the burgers on baps with lettuce and tomato and top with sour cream guacamole.