Pulse the garlic cloves and parsley in a food processor along with salt, pepper and a pinch of red pepper flakes. Add the garbanzos and fresh bread (if using) and pulse until combined. You should see pieces of garbanzo.
Beat the egg in a medium mixing bowl and mix in the garbanzo mixture. You should have a mix that is wet enough to hold its shape without falling apart when fried in oil. Add more bread crumbs or a teaspoon of water until you get the right consistency.
Form into large oval shapes that fit in the palm of your hand. You should have enough mix to make six.
To fry, heat and inch or so of oil in a small pan until very hot.
Add the rellenos in batches and fry until golden brown, turning as necessary to get a nice color all over. Drain on paper towels.
To serve, ladle some of the garbanzo broth into a bowl and place a relleno in the center. Garnish with some chopped parsley.