French Onion Soup Bombs

Preheat oven to 350° and line a medium cooking sheet with parchment paper. In a large pot over medium heat, melt butter. When melted, add onions and thyme and season with salt and pepper. Cook, stirring occasionally, until onions are soft and caramelized, about 20 minutes. Remove thyme and add wine. Bring to a simmer and cook until wine is mostly evaporated. Add in flour and garlic and cook until garlic is fragrant, 2-3 minutes. Add in broth and bring to a simmer. Let simmer until thickened slightly, 5 minutes. Season with more salt and pepper if desired. Meanwhile, prep the rolls: cut the top 1/4 off each roll. Using a paring knife, hollow out each and lay a slice of swiss over each to cover the hole, pressing in slightly. Place rolls on prepared baking sheet and toast until cheese is melted, 6-8 minutes. When cheese is melted and soup is ready, ladle soup into each roll. Top with a handful of gruyere and place back in the oven to melt. If desired, broil. Garnish with parsley and serve.