Using the flat side of a knife, mash the garlic and a large pinch of salt together on a cutting board to make a paste. Place the mixture in a bowl (or molcajete) and add the lime juice, avocado, tomato, onion, pepper and cilantro. Stir to combine. If desired, mash some of the avocado with a fork to get a smoother consistency. Season the guacamole with salt to taste. Serve with spiced pita chips.