Peel eggs. Slice each egg in half lengthwise; remove yolk. Reserve yolks for another use. Finely chop egg white. Set aside.
Coat a (7 1/2 x 3-inch) loaf pan with cooking spray; line pan with plastic wrap. Set aside.
Place broth in a 2-cup glass measure; sprinkle gelatin over broth. Let stand 5 minutes. Microwave broth mixture at high 30 seconds; stir until gelatin dissolves. Chill 15 minutes or until mixture begins to thicken.
Place trout in a food processor; pulse 10 times or until finely chopped. Add broth mixture, lemon juice, and pepper; process until well combined. Place trout mixture in a large bowl; fold in sour cream substitute, 1/4 cup chives, and dill. Spoon trout mixture into prepared pan; cover and chill overnight. Sprinkle with egg white. Garnish with chives, if desired.