#1 For Caramelized Onions: In an extra-large, high-sided skillet, melt butter over medium heat. Add the onions and sauté, tossing occasionally with tongs until onions become translucent. Continue tossing as onions become softer and begin to develop color. Season with salt. Continue tossing for a total of 90 minutes #2 Be patient, desired deep caramel color and full flavor develop during the final 15 minutes. Onion volume will reduce from filling a skillet to ¾ cup. Set aside to cool #3 For Egg Wash: In a small bowl, beat egg and milk together with a fork to create an egg wash set aside #4 For Baked Brie: Pre-heat oven to 400 °F. Line a rimless baking sheet with parchment paper or a silicon baking mat. Unfold thawed pastry sheet onto a lightly floured surface roll flat with rolling pin #5 In the center of the sheet, spoon the prepared caramelized onions in a circle shape matching the diameter size of the cheese wheel. Place the whole cheese wheel in the center, topside down, covering the onions. Gradually bring all sides of pastry sheet up over the cheese until completely covered #6 Invert use a pastry brush to brush the sides and top of the pastry evenly with egg wash (discard remaining egg wash). Place seam side down onto prepared baking sheet. Bake 30 minutes or until golden brown. Transfer baked brie to serving platter. Let stand 20 to 30 minutes before slicing. Serve as desired with fresh strawberries, grapes, crackers or crusty bread. Optional garnish: rosemary sprigs and pomegranate arils.