In a small bowl mash the avocado, cilantro, lime, and a pinch of salt and pepper to taste with a fork. Spread the mixture on the toasted bread. Sprinkle red pepper flakes if desired.
Preheat a nonstick pan over medium heat, warm the roast beef on each side. Toast bread in a toaster until golden and crispy.
Preheat a nonstick pan on medium heat with oil. Crack eggs on a flat surface and into the pan being careful not to break the yolk. Cook until the egg white is firm about 3 - 4 minutes.
Spread the avocado onto the bread, top with the roast beef and eggs, serve with grapes on the side. Sprinkle with salt and pepper before serving if desired.