3/4 C. plain nonfat yogurt
1/2 tsp dried rosemary, crumbled
1 lb. skinless, boneless salmon fillets
1 envelope (1/4 ounce) unflavored gelatin
2/3 C. reduced-fat sour cream
1/4 C. drained prepared horseradish
2 T. grated onion
2 tsp grated lemon zest
3 T. fresh lemon juice

Spoon yogurt into a paper towel-lined sieve set over a bowl. Let drain while you cook salmon. In large skillet, bring 2 C. water and rosemary to a boil over medium heat. Reduce to a simmer, add salmon, cover, and cook 12 minutes or until just cooked through, turning salmon over once. Lift from cooking liquid and cool to room temperature. Meanwhile, in small measuring cup, sprinkle gelatin over 1/2 C. cold water. Let stand 5 minutes or until softened. Set C. in small saucepan of simmering water and heat until gelatin has melted. Transfer to food processor along with salmon, sour cream, horseradish, lemon zest, lemon juice, salt, and drained yogurt. Pulse until mixture is smooth. Transfer to decorative bowl (or fish-shaped mold), cover and refrigerate at least 4 hours for mousse to set. If you like, un-mold onto a platter.