Heat a cast iron skillet to medium.
Roast 1 head of garlic, separated into cloves, unpeeled until the peels are dark, about 12-15 minutes.
Cool, then peel the cloves.
Put the cloves, parsley, oatmeal, lemon zest, lemon juice, red pepper flakes, and salt in a blender.
Blend until a pesto-like sauce forms.
Store in a covered jar for about 10 days.