On a preheated griddle or skillet at medium, toast the dried chile de arbol and California peppers. You will toast just for 1 or 2 minutes. They will soften slightly and become aromatic. Some blackening is ok. Be careful not to let them burn or they will become bitter.

Remove the chiles from griddle and transfer them to a pot of simmering water. Cook for 6 minutes and remove the whole pot from the heat. On that same griddle at medium heat, add the tomatillos and garlic. Drizzle on just a touch of oil. Roast, turning as needed, until most spots on tomatillos char and start to soften. Remove the garlic after 15 minutes.

Peel the skins off garlic, add to blender along with the charred tomatillos. Using a slotted spoon, add the chile de arbol and California peppers. Add a splash of cooking water, pinch of Mexican oregano and salt to taste. Start by pulsing and then blend on high until smooth. Taste for salt. Cool completely before storing in an airtight container in the refrigerator. The salsa will be good for up to 2 weeks.