Preheat the oven to 350 degrees.
Cover the chicken with 1 Tbsp. extra virgin olive oil and then season with the chicken seasonings above on both sides.
Cook in large Dutch oven over a medium flame with additional 1 Tbsp. of extra virgin olive oil from the chicken ingredients above. 2 minutes per side for chicken thighs. Use 3 minutes per side if you are using chicken breasts.
Remove the chicken from the pan and set aside.
Add the extra virgin olive oil and heat on medium. Then add the onions and shallots.
Cook stirring on a regular basis for 15 minutes to caramelize.
Add in the garlic and butter. Cook another 5 minutes stirring regularly.
Add the white wine and deglaze the pan. Cook for 3 minutes, scraping the brown bits from the bottom. Let the wine reduce by at least 2/3.
Then add 2 cups of beef stock, the Worcestershire sauce and the beef bullion.
Add in the thyme, salt and pepper and stir. Simmer 5 minutes on low.
Add the chicken back in and spoon the sauce over it to keep it from drying out. Cover and bake for 15- 20 minutes.
When done, add on the Gruyere cheese and cover with the lid to melt it.
Add additional thyme, sea salt and pepper to taste.
Serve over potatoes (mashed or otherwise).