Place a large, high-sided skillet over medium-high heat with 1 turn of the pan of EVOO, about 1 tablespoon. Add onion and garlic to the pan, season with salt and pepper, and cook until tender, 5-6 minutes.
Add the collard greens to the pan and continue cooking until they begin to wilt a bit, 2-3 minutes. Add the smoked turkey leg to the pan and enough chicken stock to just cover the greens. Season with salt and pepper, put a lid on the pan and cook until the greens are wilted and tender, about 30 minutes. Serve.