Preheat the oven to 425 degrees fahrenheit and line a medium baking sheet with parchment paper.
Husk and scrub tomatillos and scrub jalapeños. Place tomatillos and jalapeños on the lined baking sheet. Place garlic cloves, with their papery peels still on, onto the baking sheet.
Transfer the baking sheet to the oven and roast for about 15 minutes, or until the bottoms of the tomatillos and jalapeños are golden brown. Flip the tomatillos and jalapeños.
Continue roasting for about 5 minutes, or until the garlic cloves are roasted and tender. Remove the garlic cloves and return the baking sheet to the oven.
Broil on high for 3-5 minutes, if desired, to continue browning and charring the tomatillos and peppers. Remove from the oven and let cool for about 5 minutes.
If desired, remove the seeds and membrane from one or two of jalapeños. Remove the papery peels from the garlic cloves.
To a heatproof blender or food processor, add the roasted garlic, tomatillos, jalapeños, shallot, lime juice, cilantro, and salt. Blend or pulse until ingredients are roughly chopped but well combined.
Let cool and chill in the refrigerator for about 4 hours, then sprinkle with crumbled cotija cheese and enjoy!
