1. To caramelize the onions, heat a large skillet over medium-low heat. Add the butter, and allow it to melt and foam, then reduce the heat to low.
2. Add the onions, thyme leaves and a pinch of salt to the skillet. Cook for one 1 hour, stirring every 10-15 minutes, until the onions are soft, golden brown and caramelized. If the pan gets too try during the cooking process, add a teaspoon of water.
3. Remove the onions from the heat and add balsamic vinegar. Taste the onions and season with additional salt and pepper, if desired. Set aside or cover and refrigerate until ready to use.
4. Preheat oven to 180ºC.
5. Place Castello Creamy White into a small oven dish. Cover the dish and bake for 10 minutes until melted and bubbly.
6. Remove from oven and allow to rest for 5 minutes. Garnish with the caramelized onions and serve with toasted baguette slices and/or crackers.
Other great toppings for baked Creamy White are: blanched fresh asparagus spear pieces, pickled plums, pears or raspberries with balsamic vinegar.