Tiny quail eggs cooked in small heart-shaped toasts, plus creme fraiche and caviar makes for a luxurious first course.
Place beets in a large saucepan; cover with salted water. Set over high heat, and bring to a boil. Reduce heat to medium high, and cook until fork tender, about 40 minutes. Remove pan from heat, and let beets stand until cool enough to handle. Remove skins, and cut into 1/4-inch dice. Set beets aside.
Heat oven to 200 degrees. In a medium bowl, whisk together the vinegar, lemon juice, shallot, mustard, and olive oil until combined. Season with salt and pepper. Set the vinaigrette aside.
Using a 2 3/4-inch-wide heart-shaped cookie cutter, cut out a heart from each bread slice. Using a 1 1/8-inch-wide heart-shaped cookie cutter, cut out centers from larger hearts. Using remaining bread pieces, cut out twelve more small hearts; you should have a total of twelve large and twenty-four small hearts. Set all the hearts aside.
Line a baking pan with parchment, and set aside. Crack the quail eggs into twelve individual small dishes, such as teacups or ramekins, and set the dishes aside.
In a large skillet, melt 1 tablespoon butter over medium heat. Place six large and twelve small hearts in the skillet. Cook until golden brown on one side, about 2 minutes. Turn hearts over, and reduce heat to medium low. Carefully pour an egg into the center of each large heart, adding just enough of the white to fill the hole. Cover, and cook until the eggs have just set, about 2 minutes. Transfer the eggs and toasts to prepared pan, and cover with aluminum foil. Transfer to oven to keep warm. Set small hearts aside.
Wipe out the skillet, and repeat step five with the remaining tablespoon butter, large and small hearts, and the eggs.
Place creme fraiche in a pastry bag fitted with a #12 plain tip. Pipe dollops onto small hearts; top each with 1/8 teaspoon caviar. Set the caviar croutons aside.
Remove baking pan from oven. In a large bowl, toss the mesclun and the reserved beets with the vinaigrette, and divide among twelve plates. Place an egg nest on top of each salad, and garnish each plate with two caviar croutons. Serve.