Step 1 Preheat your oven’s broiler to high and place the rack 3 inches (8 cm) from the flame. Line a baking sheet with aluminum foil for easy clean up.
Step 2 Cut the tomatillos in half and place them cut side down on the baking sheet along with the onion and jalapeños.
Step 3Spray or brush with a small amount of olive oil. Broil for 5 minutes until charred.