Make the stuffing: Heat the olive oil in a wide saucepan over medium heat. Add the onion, fennel chunks and 3/4 teaspoon salt and cook until slightly soft, about 7 minutes. Add the coriander and cumin and cook for 1 minute. Stir in the quinoa and broth and bring to a simmer; cover and cook over low heat until the quinoa is tender, 10 to 12 minutes. Let cool slightly, then add the scallions, dried apricots, pistachios, olives, parsley, orange zest and juice, fennel fronds, 1/2 teaspoon salt, and pepper to taste. Toss to combine.
Prepare the capon: Season the inside of the bird with salt. Fill the cavity with the quinoa stuffing and tie the legs together. Place any extra stuffing in a small oiled baking dish, cover with foil and set aside. Brush the capon with 2 tablespoons olive oil. Mix the coriander, cumin and paprika in a small bowl. Rub the spice mixture over the capon and season with salt.
Pour 1 cup water in the bottom of a large roasting pan; place a rack in the pan. Place the capon on the rack, breast-side down, and roast about 30 minutes. Turn the bird breast-side up, reduce the oven temperature to 350 degrees F and roast until a thermometer inserted into the thigh registers 165, 1 hour 15 minutes to 1 hour 30 minutes. Place the dish of extra stuffing in the oven about 15 minutes before the capon is done and cook 20 to 30 minutes. Let the capon rest about 15 minutes before carving.
If you are concerned if the oils or other ingredients in these recipes are suitable for Passover, seek non-dairy substitutes or ingredients that are certified kosher for Passover.