Preheat oven to 425˚F (220ºC).
Blot dry the chicken all over, including the cavity, with paper towels and generously season with kosher salt. (If time allows, see notes below for seasoning the chicken and letting it rest overnight.)
To a 9-13-inch baking dish, add beans, all but two slices or ends of the lemon, garlic cloves and rosemary. Drizzle olive oil over and toss. Pour in broth. Set whole chicken atop the bean mixture and insert remaining lemon slices and a few sprigs of rosemary into the chicken cavity. Drizzle olive oil over the chicken and a little more over the beans, just enough to keep the beans from drying out.
Roast the chicken until the outside is deeply golden brown and internal temperature reaches 165˚F (75ºC) on a digital thermometer, about 60 to 80 minutes. If you have a large bird (5 pounds), plan on adding more time, checking in 5-minute increments so that you don’t overcook it. For smaller birds (3 pounds), start checking at 50 to 60 minutes.
Remove chicken from oven and let rest in pan for 10-15 minutes.
Transfer chicken to a platter or cutting board. Remove aromatics from the cavity, carve and serve together with bean mixture and any sides of your choosing.