Chipotle Chicken Skillet with Sweet Potatoes and Chickpeas

olive oil, divided

boneless, skinless chicken breasts, cut into bite-size pieces

kosher salt, divided

freshly ground black pepper, divided

sauce, from canned chipotle chiles in adobo, plus additional to taste

medium sweet potato, peeled and cut into 1/2-inch cubes (about 10 ounces)

to 2 whole chipotle peppers from canned chipotle peppers in adobo, diced (I used 2, and the recipe had a pretty good kick—use less if more sensitive to spice)

low-sodium chickpeas, rinsed and drained

cherry or grape tomatoes, halved

medium green onions, chopped (about 1/2 cup)

lime juice (about 1/2 lime)

chopped fresh cilantro (optional)