Preheat oven to 425°.
Season chicken with salt and pepper. Heat oil in a large (at least 5.5 qt) dutch oven over medium–high heat. Place chicken, legs side down and using tongs or your hands, press lightly to make sure the skin comes into even contact with the pot.
Cook, without moving, until chicken is nice and browned, 5–8 minutes.
Add lemon slices, maneuvering the chicken however you need so that the slices come into contact with the bottom of the pot.
Let the lemons sizzle in the chicken fat until caramelized on one side, about 2 minutes. Add shallots, dates, thyme and 2 cups of water. Sprinkle the top of the chicken with crushed red pepper flakes and place the lid on.
Place dutch oven in the oven and roast until the dates are plump, the lemon is jammy and the chicken is almost but not totally cooked through, 20–25 minutes.
Remove the lid and continue to cook until the liquid has reduced by ½ and the top of the chicken has an illustrious golden-brown color, another 20–25 minutes.
Remove from oven and let chicken rest in the dutch oven for 10 minutes before transferring it to a cutting board and carving. Serve alongside shallots, lemons, and dates with some more thyme sprinkled over.
