Preheat the oven to 400 degrees.
Toss the sliced mushrooms with the olive oil then season with sea salt and freshly cracked pepper, to taste.
Place the mushrooms on a rimmed baking sheet in a single layer. Add four sprigs of fresh thyme to the top then place in the oven to bake for 20 minutes, stirring halfway through, until golden brown and tender.
Add half of the minced garlic and stir to coat evenly, continue roasting for another five minutes. Remove from the oven and discard the thyme sprigs; set aside.
Heat the butter in a large stockpot or Dutch oven over medium heat. Add the onion, and cook, stirring often, until softened and golden, about 12-15 minutes.
Add the minced garlic, and cook, stirring constantly, for 1 minute.
Whisk in the flour and cook, whisking constantly, for 2 minutes.
Add the wine and whisk for 1 minute making sure to scrape up the browned bits from the bottom of the pot.
Add the chicken broth, bay leaves and remaining thyme sprigs. Bring to a boil; reduce heat and simmer until slightly reduced, about 20 minutes. Remove the bay leaves and thyme sprigs.
Add the mushrooms and their juices back to the soup along with the cream. Taste and season with sea salt and freshly cracked pepper, to taste. Serve immediately. Enjoy.