Step 1Heat a comal or large cast-iron skillet over medium-low heat. Place both chiles and the garlic on the hot surface in a single layer. Toast, turning often, until the chiles are brittle and a shade darker and the garlic is blistered in spots, 3 to 4 minutes.
Step 2Transfer the chiles and garlic to a food processor and pulse until finely chopped. Scrape the bottom and sides of the bowl and add the oil, sesame seeds and salt. Pulse until well mixed. Zest the orange peel directly into the processor, then halve the orange and squeeze in its juice. Pulse once or twice just to incorporate. Taste and season with more salt if needed.