Trim Outer Leaves From Fennel; Reserve 1 T. Feathery Leaves. Cut Fennel Bulb in Half Crosswise & Then Lengthwise Into Thin Slices. Combine Fennel Bulb, Reserved Leaves, Orange Rind, Salt, Pepper, Fennel Seeds, Orange Juice & Oil in A Medium Bowl, Tossing Gently. Cover & Chill. Drain, Reserving Liquid. Spoon Fennel Mixture Into Center Of A Round Serving Platter. Arrange Oranges & Grapefruit Around Fennel Mixture; Top With Onion. Place Radicchio Around Outside Of Platter, Tucking Leaves Under Orange & Grapefruit Slices. Drizzle With Reserved Orange Juice Mixture. (Fat 2. Chol. O.)