• Onions: In a soup pot or Dutch oven, heat the olive oil over medium heat. Add onions and sprinkle with salt. Stir often; cook the onions until they begin to brown, about 8 minutes. Add the garlic and thyme; cook, stirring occasionally, for about 2 minutes. Using a slotted spoon, remove the onions and set aside, leaving the oil in the pot.
• Mushrooms: Add mushrooms to the pot you cooked the onions in. Arrange the mushrooms in a single layer at the bottom of the pot. Sprinkle with salt and cook undisturbed for about 5 minutes. Stir 1 to 2 more times and continue to cook until golden brown all over, about 5–7 minutes longer.

  Sprinkle the mushrooms with flour and toss to coat evenly. Cook for another 2 to 3 minutes undisturbed. Add the sherry and cook the mushrooms undisturbed for another 3 to 5 minutes. The mushrooms should be very brown and possibly caramelized.
• Stock: Add the stock and onions to the mushrooms. Bring to a boil. Once boiling, reduce the heat, cover, and allow to simmer for 20 minutes. Remove from heat. Add the 2/3rds of the cream to the soup and stir.
• Creamier Soup: Take up to 1/3 of the soup and place it in a blender. Blend until smooth. Return to the pot and stir to incorporate.
• Serve: Pour into bowls, then top with remaining cream and desired garnishes.

Garlic Croutons (optional)

• Prep: Preheat the oven to 350. Line a baking sheet with parchment paper. Cut the bread into cubes.
• Make and Bake: Toss the bread cubes in olive oil and garlic salt. Arrange on a baking sheet. Bake for 12 to 15 minutes, until the croutons reach your desired level of toastiness.