Combine first 11 ingredients in a large bowl and mix well.
Heat a large frying pan and add some oil. Fry a small amount of the burger mixture to check the seasoning. Adjust if necessary.
Form into 6 patties and fry for 2-3 minutes, flip and fry for another 2-3 minutes. Then flip again and fry for 1-2 minutes, flip and fry for another 1-2 minutes or until cooked through to your preference. You can of course do the same thing on a hot grill. After flipping the burger the first time, place a slice of cheese on the patty and allow to melt while the patty is cooking. Serve on hamburger buns with guacamole.