In a food processor or blender, blend the avocados with the lemon juice to make a smooth puree. Season to taste with salt and pepper. Mix the fromage blanc with the chopped chives (save a little of the chives for decoration).
Layer the verrines with the pureed avocados, then the fromage blanc and finally the smoked salmon. Garnish with remaining chives. Refrigerate.
Makes 12 servings.