In a saucepan over a medium heat, add the butter, onions, and 1/3 of the oil. Stir together and cover with a lid. Cook until onions are softened and deep golden brown, stirring occasionally.
Add the garlic and turkey and cook for 2-3 minutes while breaking up the turkey into smaller pieces. Stir in the flour and cook for 2 minutes.
Add the broth, thyme, salt and pepper and bring to a simmer. Stir together and reduce the heat slightly. Cover with a lid and simmer for about 20 minutes.
While the soup is cooking, preheat the oven broiler to low.
Cut a circle into the bread and hollow out the center, leaving a 1-inch wall to stop any leakages. Drizzle the bread with the remaining olive oil and season with a pinch of salt and pepper. Place on a foil-lined baking sheet.
Place under the broiler for 3-5 minutes until they are nice and toasted (make sure to keep your eye on them so they do not burn).
Remove the thyme sprigs. Using a slotted spoon, scoop the onion and turkey into the bread bowls. Ladle the broth into the bread bowls and lay the cheese on top (it's okay if fillings are pouring out of the top of the bread bowl).
Broil until the cheese is melted and it's golden brown on top.
Serve immediately with a good grinding of black pepper and extra thyme.