Remove stems from chiles. Cut the guajillos in half and remove the seeds.
Place in a small sauce pot with 2 cups of water. Bring to a boil and simmer for 5 minutes.
Remove from heat. Place chiles and water in blender jar.
Cut tomatoes in quarters.
Heat a skillet to its smoking point.
Add oil and distribute in pan.
Add the tomatoes cut side down. Add the garlic and onion.
Char vegetables on all sides. The more black you get, the more flavor.
It is best to char both of the cut sides of the tomatoes first, then the skin side.
Place charred vegetables in blender with the chiles.
Add salt. Blend for 30-45 seconds or until the salsa has a smooth consistency.
Taste and add more salt if necessary.