Step 1Combine the flour, sugar, baking powder, salt and baking soda in a medium bowl. Combine the buttermilk, 2 tablespoons beaten egg and the butter in a small bowl. (Set aside the remaining egg for use in the soup.) Make a well in the center of the dry ingredients; add the liquid ingredients. Stir just until blended.
Step 2Heat a griddle or skillet over medium heat with just enough oil to coat the bottom of the pan. Spoon 1 teaspoon of batter onto the griddle or skillet for each "blini." Cook 30 seconds to 1 minute on each side until both sides are dark golden brown. Repeat until all the batter is used, adding oil to the pan as necessary. Makes about 30 "blini." Reserve in a warm place until ready to use.
Step 1Melt 3 tablespoons of the butter in a large sauce pot over low heat. Add the leeks and celery and saute about 5 minutes, stirring often, until tender. Add the garlic and cook 1 minute, or until the garlic is fragrant.
Step 2Add the mushrooms and saute until all the vegetables are tender, about 10 minutes.
Step 3Add the chicken broth, bay leaf and rosemary and bring to a boil, then reduce the heat and simmer, loosely covered, for 45 minutes. Remove bay leaf and rosemary.
Step 4Puree the soup in a blender until velvety smooth; this may need to be done in 2 or 3 batches. Rinse out the pot and pour the soup back into the pot. Bring the soup to a simmer.
Step 5Blend the remaining tablespoon butter with the flour in a small bowl. Whisk this into the soup and simmer about 1 minute until the soup is slightly thickened. In another small bowl, beat together the cream and the egg until blended. Whisk this into the soup until it is combined and the soup is slightly thickened; do not bring to a simmer or the egg will scramble. Season with one-eighth teaspoon each salt and white pepper, or to taste.
Step 6Combine the creme fraiche, chives, salt and white pepper to taste in a small bowl.
Step 7To serve, have the "blini," seasoned creme fraiche and soup on hand. Ladle about three-fourths cup soup into each of 8 shallow bowls. Use a sharp knife to cut a pocket in one of the blini. Spoon about one-fourth teaspoon creme fraiche onto each "blini" half, then put together to make a sandwich. Place 2 or 3 filled "blini" and a parsley sprig on top of each soup serving. Each serving: 191 calories; 7 grams protein; 14 grams carbohydrates; 2 grams fiber; 13 grams fat; 8 grams saturated fat; 59 mg. cholesterol; 490 mg. sodium.