Bring water to a boil in a medium saucepan. Add wild rice and 1/2 teaspoon salt; cover, reduce heat, and simmer 50 minutes or until tender. Drain and set aside.
Heat 2 teaspoons oil in a small nonstick skillet over high heat. Add mushrooms; saute 5 minutes or until browned. Remove from heat; stir in 1/4 teaspoon salt.
Combine 1 teaspoon salt, herbes de Provence, and 3/4 teaspoon pepper. Lightly coat the roast with cooking spray; rub herb mixture over roast. Place roast, bone side up, on a broiler pan coated with cooking spray; insert meat thermometer into thickest portion of roast, making sure it does not touch bone. Cover bones with aluminum foil, and place a ball of foil in the center of the roast. Place in a 500° oven; immediately reduce oven temperature to 400°, and bake 45 minutes or until thermometer registers 135° (medium-rare). Place roast on a large serving platter; cover with aluminum foil, and set aside.
Place broth in a medium saucepan; bring to a simmer (do not boil). Keep warm over low heat.
Heat the remaining oil in a large saucepan over medium heat. Add onion and celery; saute 1 minute. Add Arborio rice; cook 1 minute, stirring constantly. Add wild rice and 1/2 cup warm broth; cook 1 minute or until liquid is nearly absorbed, stirring constantly. Add the remaining warm broth, 1/2 cup at a time, stirring constantly until each portion of broth is nearly absorbed before adding the next (about 20 minutes total). Stir in remaining salt, remaining pepper, mushrooms, peas, and thyme. Cook until thoroughly heated.
Uncover roast, and remove foil ball. Spoon risotto into center of roast (if all of the risotto does not fit, serve remaining risotto in a bowl).