2 TBSP butter
3 large Vidalia (or other sweet) onions, cut into half vertically and then
sliced into thin slices (about 6 to 7 cups)
½ cup chicken stock
2 sprigs fresh thyme
½ cup Parmigiano-Reggiano cheese, shredded
½ cup Gruyere cheese, shredded
Melt butter in a large, heavy skillet over medium heat. Add onions. Stir until onions have wilted enough to make room for all of them in the pan. Cover and cook about 10 minutes or until onions are completely softened. Remove cover and stir in thyme and stock and cook uncovered over medium high heat until liquid evaporates and onions brown. Combine cheeses and stir into onions. Continue to stir until cheese melts and onions are coated. Remove thyme sprigs and allow to cool for a short time before serving.