Chipotle Chicken Fajitas

Name: Chipotle Chicken Fajitas
Ingredients: 1 pound (about 6) boneless, skinless chicken thighs, cut lengthwise into strips about 1-inch wide; 1 chipotle en adobo, minced (about 1 tablespoon); 2 teaspoons kosher salt; 1 tablespoon vegetable oil; 1 medium red onion, quartered and sliced crosswise 1/2-inch thick; 3 medium cloves garlic, thinly sliced (about 2 tablespoons); 2 medium bell peppers, stemmed, seeded, quartered lengthwise, and sliced into 1/2-inch strips; 1/2 cup low-sodium chicken broth or water; 2 teaspoons roughly chopped fresh oregano; 6 to 8 flour tortillas, warmed, for serving; Pico de Gallo salsa, optional for serving; Guacamole, optional for serving; Sour cream, optional for serving