Step 1) Rinse the dry chiles and place in a large bowl with at least 2 cups of hot water for 20 minutes, until soft.
Step 2) Heat the oil in a medium saucepan over medium heat. Add garlic and onion and cook for 2 minutes until clear. Add the tomato and cook for 3 minutes. Transfer mixture to a blender.
Step 3) Remove the chiles from the bowl, reserving the water. Discard the seeds and membranes. Place the chiles, 2 cups of the chile-soaked water, the corn starch and the bouillon powder into the blender cup. Puree until smooth.
Step 4) Transfer mixture back into the saucepan, bring to a simmer. Add the nopales and cook for 2 minutes or until warm.
This recipe is great served in tortillas as a taco or over eggs, meats, seafood or potato patties.