In a bowl, mash the avocado with a fork until smooth. Mix in the cumin, cilantro, lime, and red pepper flakes (if using). Season with salt and pepper to taste.
Preheat a non-stick pan over low-medium heat with half of the oil. Add the eggs into the pan and stir them around until they become firm and fluffy but still moist. Season with salt and pepper and set aside.
Preheat a non-stick pan over medium heat and brown the chicken sausage slices on each side.
To make the sandwich place a slice of cheese on the bread, followed by guacamole, eggs, another slice of cheese and top with a slice of bread.
Using oil as needed, heat a non-stick pan over medium-low heat and cook the sandwich on both sides until golden brown.
Cut in half and serve with sliced chicken sausage and grapes.