4 tomatillos, husked and rinsed
1 large jalapeno pepper
1 small red onion (1/2 cut into large chunks, 1/2 thinly sliced)
2 tablespoons extra-virgin olive oil
3 cups shredded rotisserie chicken (skin removed)
Juice of 2 limes, plus wedges for serving
Kosher salt
2 cups chopped watermelon
11/2 cups fresh cilantro
3/4 cup crumbled Cotija cheese (about 3 ounces)
Freshly ground pepper
12 corn tortillas
1 avocado, chopped