Heat the oven to high broil. Place the whole garlic, shallots, and peppers in the oven for 30 minutes, turning them at the 15 minute mark. Take out and let cool for ~1 hour.
Once cooled, take the charred skin off the peppers, de-seed them, and cut each into 4-5 pieces.
Unwrap the garlic cloves and squeeze the cooked garlic into a bowl. Do the same for the shallots.
You should have approximately ¼ cup of each of the peppers, garlic, and shallots. Combine the ¼ cup of each in your mortar and pestle and pound into a paste.
Add the fish sauce and adjust to your tastes.
Sprinkle coarsely chopped cilantro leaves and toasted sesame seeds (if using) on top. Enjoy with fresh or steamed vegetables, deep fried pork rinds, and jasmine rice.