Chop the stems off your tomatoes and peppers, then chop your onions in half and remove the skins.
Place your tomatoes, onions, and peppers directly on the grates of your smoker and let them smoke for 1 hour, flipping halfway through.
Remove your vegetables from the smoker and let cool at room temperature for 20 minutes.
Add your smoked vegetables to a food processor (or blender), along with the cloves of garlic, lime juice, chopped cilantro, and kosher salt.
Blend to your desired consistency (see notes below).
Notes
Depending on how you prefer your salsa, you can adjust the thickness by blending it differently. If you prefer a thick, hearty salsa, just use the pulse function on your food processor and give it 3 to 4 pulses at a time until you reach the consistency you want.If you prefer a thinner salsa, add a half cup of water before you blend, and then let the vegetables blend for 1 to 2 minutes on a medium speed. Adding ½ a cup of water will help give you a thinner, restaurant-style salsa.