Step 1: With a mortar and pestle, pound 12 basil leaves, 3 cloves garlic, 2 tablespoons pine nuts, and a pinch of salt until thoroughly mashed.
Step 2: Mix in 3 tablespoons olive oil until well combined.
Other Method: Alternatively, pesto can also be made in a blender. Blend the basil, garlic, and pine nuts, then slowly add the oil. Blend on low to a smooth paste. Season with salt.
Step 1: To assemble skewers, line up a cherry tomato, basil leaf, and a mozzarella ball on a toothpick, with the basil in the middle.
Step 2: Continue until you run out of ingredients, arranging the skewers on a large plate.
Step 3: When they've all been assembled, take your pesto and spoon about ½ teaspoon on each skewer.