In a bowl, mash together the avocado, lime juice, cumin and salt and pepper to taste. Make the mixture smooth.
Stir in parsley, set aside.
Mix equal parts of mayo and mustard and lightly spread on each bread slice.
To make sandwich: Turn one slice of bread (mayo/mustard side down) in a hot skillet. Top with cheese. Spread some of the avocado mixture on top and then top with a tomato slice and the remaining bread slice.
Cover skillet with lid and cook to allow cheese to melt and fillings to warm.
Remove lid and increase heat to medium-high.
Continue cooking until your bread is done to your liking on both sides.
Recipe by Geaux Ask Alice! at https://geauxaskalice.com/creole-tomato-avocado-grilled-cheese-sandwich/