1. Cook lentils according to package directions; drain.
2. Combine the flour, cornmeal, baking powder, baking soda, sugar, cumin, salt and pepper in a medium bowl. Combine the buttermilk, egg, and butter in a separate bowl. Stir the buttermilk mixture into the flour mixture until smooth. Batter will be slightly thick. Gently fold in lentils.
3. Heat a large nonstick skillet over medium. Drop batter 1 tablespoon at a time into skillet. Cook pancakes until the tops are just covered with a few bubbles and the edges are set, about 2 minutes. Turn and cook until browned, about 2 minutes longer. Transfer to a baking sheet and repeat with remaining batter.
4. To assemble, top pancakes with salmon and 1/2 teaspoon crème fraiche; garnish with the chives. May be made advance and refrigerated up to 4 hours ahead.