In a cast-iron pan, toast the almonds, árbol chilies, and whole garlic cloves over high heat, tossing occasionally until they darken (not burned) and begin to smoke.
Turn the heat off and let cool on the stove. Once the mixture is cool, transfer to a food processor and add the chopped tomatoes, red wine vinegar, parsley, and egg yolk. Blend in the food processor until it forms a thick paste.
Slowly add the oil while keeping the food processor running. Once all the oil is fully incorporated and the sauce is smooth, remove from the food processor and season with salt to taste.