Salads: Chicken, Squash, Chickpea Salad with Tahini Dressing

To serve 4:
1 medium butternut squash (about 2 pounds), peeled, seeded, cut into 1" pieces
4 T olive oil
Kosher salt & black pepper
2 6 oz boneless, skinless chicken breasts
1/3 cup tahini
2 T fresh lemon juice
1 t dried oregano
12 oz romaine hearts, cut into strips (about 9 cups)
1 15.5 zo can chickpeas, rinsed (I used cannelini beans)
1 cup pita chips, broken
2 T chopped fresh chives

Heat oven to 425 F, with racks in upper and lower thirds.  On a rimmed baking sheet, toss squash with 2 T oil, 1/2 t salt, 1/4 t pepper.  Roast on bottom rack, tassing once, until tender, 25-30 minutes.
Place chicken on second rimmed baking sheet and coat with 1 T oil, 1/4 t salt, 1/4 t black pepper.  Roast on top rack until cooked through, 15-20 minutes.  Let cool slightly and slice.
In small bowl, whisk together the tahini, lemon juice, oregano, 1 T oil, 1/3 cup water, 1/4 t s, 1/4 t pepper.  Divide lettuce among plates;  top with squash, chicken, chickpeas, pita chips, and chives.  Serve with dressing.