Roast the chicken. Preheat the oven to 375 degrees F. Using a sharp knife or kitchen shears, cut along both sides of the backbone and discard it. Flatten the chicken and cut it in half through the breast so you have two halves-each with a leg and breast. Rub all over with some of the smoked olive oil, ensuring it gets in all the crevices. Season all over with salt and pepper.

Set the chicken in a large roasting pan over two burners and heat over medium-high heat. When the pan is hot, add the chicken halves skin-side down and sear for 4 to 5 minutes. Turn the chicken over, add the potatoes to the pan, and drizzle with more smoked olive oil. Season with salt and pepper. Roast in the oven for 45 minutes, or until an instant-read thermometer inserted in the joint between the thigh and drumstick reads 160 degrees to 165 degrees F. The potatoes should be golden on the outside and tender in the middle. Remove from the oven and allow the chicken to rest for 5 minutes.

Make the citrus salsa. Use a sharp knife to cut away the rind and pith from each of the citrus fruits. Holding the fruit over a bowl, carefully cut between the membranes to free the segments. Let the juices and segments fall into the bowl. Add about cup extra-virgin olive oil to the bowl and season with salt and pepper. Cut the radishes into very fine matchsticks on a mandoline or with a sharp knife. Fold them into the citrus salsa, and add the chives.

Serve the roasted chicken with the potatoes and citrus salsa, and garnish with flowering cilantro. Season with fleur de sel.