Combine all topping ingredients in a bowl and set aside.
Heat grill on medium.
In a large bowl, combine all burger ingredients and mix until just combined. Do not over mix.
Divide mixture evenly into four and make patties approx 1 to 1 ½ inch in thickness. Grill burgers 5 to 7 minutes each side or until the internal temperature reaches 170ºF (77ºC).
Spread some guacamole on the bottom half of each bun, top with shredded lettuce, the Tex–Mex burger and a few spoonfuls of the tomato topping mixture. Enjoy.