In a Dutch oven over large, deep, skillet, heat butter and one tablespoon of the olive oil over medium heat. Add onions and cook them, stirring occasionally until softened and liquid has begun to evaporate - about 20-25 minutes. Stir in the salt and pepper and reduce heat to medium-low. Cook the onions gently, stirring occasionally until they are deeply golden brown - about 50 minutes to an hour. 

Meanwhile, pour the stock in another Dutch oven and add the herbs. Bring the stock to a boil, then turn off the heat, cover and allow to steep for flavor while the onions cook. 

Once the onions are fully caramelized, stir the garlic into them. Then stir the flour throughout the onions and cook for a minute or two. Gradually stir in wine and turn off the heat. 

Now transfer all the onion mixture into the stock mixture and stir to combine. Heat to a simmer  and let cook, uncovered, until the flavors are blended, about 30 minutes. Stir in the brandy or whiskey and taste for salt and pepper seasoning. Keep the pot warm on low heat. 

Preheat the broiler to high. Place your ovenproof bowls on a sheet pan and fill each with soup, making sure to get plenty of onions. Lay one piece of bread gently on top of the soup and then divide the cheese equally among the bowls, on top of the bread. 

Slide the sheet pan with the bowls under the broiler and watch closely. The soup is ready when the cheese is melted, bubbly and golden brown. You may need to rotate the pan to get everything evenly browned. 

Once the soup is done remove the sheet pan from the oven and very carefully transfer the hot bowls of soup to rest on a dinner plate.