In sauté pan, cook bacon until browned and crispy. Remove to paper towel lined plate and set aside. In small bowl, whisk together the mayonnaise, liquid smoke, green chilies, cumin and paprika.
Spread some of the mayonnaise mixture on each slice of bread. Top each slice of bread with two slices of the cheddar cheese. On two slices, top each with three pieces roast beef. Divide the pickles, tomato, onions and bacon on the meat topped bread. Top with the remaining two slices bread.
In bowl, mix together the butter and salt. Spread some of the butter on the top sides of each sandwich.
Place in preheated pan on medium heat, butter side down. Butter the top side of the sandwiches. Cover and cook until the bottom is browned and crispy – about 2-3 minutes. Flip the sandwiches, cover and continue cooking until the bottom is browned and crispy. Slice and enjoy.