1 teaspoonfresh herbs,chopped (rosemary works well)
Caramelizing the Onions
Heat up a large heavy bottom skillet over high heat (don't use non-stick here unless that's all you have). Add the thinly sliced onions and turn heat down to medium high. Let cook for 3-4 minutes then start to stir using a wooden spoon. You want to wait until they start sticking to the bottom of the pan and getting brown so if you start stirring and they're not to that point yet, let them keep cooking for an extra 2 minutes. Use the wooden spoon to scrape up any browning form the bottom of the pan and stir occasionally for 3-4 more minutes.
Turn the heat down to medium and add in the sugar, butter and salt. Starr occasionally and cook the onions until caramelized 10-15 more minutes. Set aside to cool
Assembling the Galette
Grate the gruyere cheese and toss with the caramelized onions.
Roll out the pie crust to a large circle. Spoon out the onion and cheese mixture to the center of the pie crust, piled high. Fold the edges of the crust up onto the onions.
Place prepped galette in the refrigerator for 30 minutes.
Preheat oven to 375 degrees.
Brush a whisked egg over the edges of the crust (you don't need much but this will make the crust golden brown. Sprinkle the crust with extra sea salt and freshly ground pepper.
Bake for 40-50 minutes or until crust is golden brown.
Sprinkle finished galette with fresh herbs. Let cool slightly then serve. This can be served with a green salad for a meal or as an appetizer.
If you can't find gruyere cheese, white cheddar also works well.