Food & Cooking Recipes Appetizers Caramelized Onion Tartlets 3.0 (108) 6 Reviews By Martha Stewart Editors Martha Stewart Editors Facebook Instagram Twitter Website An article attributed to "Martha Stewart Editors" indicates when several writers and editors have contributed to an article over the years. These collaborations allow us to provide you with the most accurate, up-to-date, and comprehensive information available.The Martha Stewart team aims to teach and inspire readers daily with tested-until-perfected recipes, creative DIY projects, and elevated home and entertaining ideas. They are experts in their fields who research, create, and test the best ways to help readers design the life they want. The joy is in the doing. Editorial Guidelines Updated on August 24, 2017 Print Share Share Tweet Pin Email Servings: 6 Cipollini onions are perfect for these tarts because they are small, flat, and sweet. You can also substitute shallots. Ingredients All-purpose flour, for dusting Pate Brisee (Pie Dough) 3 tablespoons butter 6 tablespoons sugar 12 cipollini onions, peeled Salt and freshly ground black pepper 1 tablespoon balsamic vinegar 2 sprigs fresh thyme Directions On a lightly floured work surface, roll pate brisee to 1/8-inch thickness. Using a 2-inch-round biscuit cutter, cut out 12 circles. Transfer to a parchment-lined baking sheet, and refrigerate until needed. Melt butter in a heavy-bottomed skillet over medium heat. Sprinkle sugar over butter; cook, stirring, until sugar melts and starts to turn amber in color. Halve onions crosswise. Season cut surface with salt and pepper. Arrange onions in a single layer, cut side down, in skillet. Cook over medium-low heat, without turning, until caramelized sugar bubbles up around onions and onions are fragrant, about 15 minutes. Remove from heat. Using a slotted spoon or spatula to keep onions intact, transfer them to mini-muffin tins, placing half an onion, cut side down, in each cup (allow sugar syrup to remain in pan). Return skillet to low heat. Stir in balsamic vinegar, and season with salt and pepper and a few leaves of fresh thyme. Heat oven to 425 degrees. Quickly, before sugar cools, spoon a generous teaspoon sugar mixture into each muffin tin. Drape chilled pastry rounds over each onion, and using fingers, press to secure. Onions should be swaddled in pastry. Place muffin tin in oven; bake until pastry is golden brown and sugar bubbles up over pastry, about 20 minutes. Remove from oven. Immediately set baking sheet over muffin tin; invert, being careful of hot caramel that might drip from tin. Once you invert the tins, tarts will be right side up; serve garnished with fresh thyme leaves. Print