Place the chicken pieces, one at a time in between two layers of wax paper or in a large zip-style bag. Using a rolling pin or meat tenderizer pound chicken to about ½-inch thickness. Using a sharp knife, cut the chicken breasts in half.
In a clean zip-style bag add the ingredients for the marinate. Squish together good with your fingers. Place flattened chicken pieces in the bag and refrigerate for a minimum of 2-3 hours.
Grill in a hot pan over medium heat, in 2 tablespoons of canola oil and 1 tablespoon of butter, for about 2-3 minutes per side or until no longer pink inside. Use tongs to flip over.
Let rest briefly before assembling on rolls. Spread a thin layer of mayonnaise on one side of a kaiser roll.
Top chicken with slices of fresh tomatoes, lettuce, avocado and Cabot cheddar cheese.