Take a link of the Mexican chorizo sausage and slice lengthwise.
Pre-heat grill. Place chorizo on the grill and cook for 25-30 minutes. Use tongs to turn links often until golden brown.
Slice bolillo buns lengthwise but not all the way through (think hot dog bun style).
Place cooked chorizo sausage in the bolilllo and add grilled avocado and tomato - or enjoy on the side.