Wash and trim beet (do not peel). Cook, covered, in lightly salted boiling water for 35 to 45 minutes or until tender. Drain and cool slightly. Slip skin off beet and slice into 14-inch slices. Using a 1-1/2-inch heart-shape cookie cutter, cut beet slices into hearts if desired.
Meanwhile, preheat oven to 350 degrees F. In a medium saucepan combine broth and water. Bring to boiling. In a 2-quart souffle or casserole dish combine broth mixture, rice, onion, oregano, oil, and salt. Bake, covered, about 40 minutes or until rice is tender. Stir in cheese.
Top risotto with beets. Return to oven and bake, uncovered, 5 minutes more. Makes 8 side-dish servings.