In a heavy bottom stock pot or dutch add the oil and butter and melt over over medium-low heat. Add sliced onions and carefully stir so they are evenly coated with the butter and oil. Add a small bunch of fresh thyme tied in a little bundle. Cover and cook for 25 minutes until they are translucent. Remove the lid, turn the heat to low, add sugar and kosher salt and continue to cook uncovered, stirring frequently until the onions have browned, caramelized and reduced in volume, about 15 minutes.
Once caramelized, reduce heat to medium-low again and add the flour, stirring to coat the onions. Brown the flour for about 2-3 minutes. Stir in about 1 cup of beef stock, scraping the bottom of the pan to get up all of the cooked-on bits. Add the rest of the stock, sherry, and bay leaf. Simmer for 30 minutes.
Check the soup for seasoning and add salt and fresh cracked black pepper if needed. Remove the bay leaf pour into a bowl and serve or set aside.
Brown the chicken drumsticks in olive oil and a pinch of red pepper flakes.
Drain excess oil and place chicken back in the same pot with chopped carrots and celery.
Place 4 cups of onion soup in a blender and pulse until chunky, not puréed completely. It needs to still have some body. Add the blended French Onion soup over to just cover and add in another thyme bundle.
Cover and cook on a low simmer for 30 minutes or in a 350°F oven for the chicken to be fall apart tender and the vegetables were still al denté.
Serve 2-3 drumsticks in each bowl and spoon vegetables and soup over. Chop the fresh chives as a nod to the onion and garnish on top.