1. Preheat oven to 400 degrees. Spread bread squares evenly on a baking sheet. Bake until edges are lightly golden, 7 to 10 minutes, and set aside to cool.

2. Peel eggs, and cut in half lengthwise. Carefully scoop out the yolks, and reserve. Cut whites in half again lengthwise, and arrange quarters on toast squares at a diagonal.

3. Using a stiff rubber spatula, push the yolks through a fine mesh sieve placed over a small bowl. Stir in creme fraiche, heavy cream, salt, and pepper.

4. Transfer yolk mixture into a medium-size pastry bag fitted with an open-star tip (Wilton No. 32). Pipe mixture into egg-white quarters, about 3/4 teaspoon for each quarter. Spoon a dab of caviar over piped yolks, and garnish with a chive.