Preheat the oven to 350 degrees F.
Crack the eggs on top, and using an egg cutter, slice the tops off the eggs. Carefully pour out the contents of 5 of the eggs into a bowl and separate the yolks from the whites. Transfer the yolks to another bowl. (Use the 5 egg whites and the contents of the remaining 7 eggs for other dishes). You need a total of 12 egg shells for this recipe. Add the cream and roasted garlic to the 5 yolks and whisk thoroughly; season with salt and pepper.
Carefully rinse out the hollowed eggs under cold running water and return them to the egg carton. Pour the whisked egg mixture into each hollowed egg so that it fills the shell halfway. Place the carton in a roasting pan. Pour enough warm water into the pan to come halfway up the sides of the eggs. Cover the pan with foil and put it into the oven. Cook for about 20 minutes, or until the custard is firm and does not break when touched with your finger.
While the eggs are cooking, pour the oil into a heavy skillet and set over medium-high heat. When the oil is hot and shimmering, add the mushrooms and saute for 2 minutes. Add the tomatoes and continue to saute until most of the liquid has evaporated. Add the vinegar, season with salt and pepper, and sprinkle with the chopped parsley.
Remove the eggs from the oven, and divide the mushroom-tomato mixture between the eggs, spooning it carefully over the custard inside the eggs.
To serve, arrange the 3 types of peppercorns in the bottom of a serving dish, platter, or basket. Set the filled eggs upright on the peppercorns and serve with demitasse spoons.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.