While you could certainly enjoy this for dinner, I love making a batch and packing it up in a thermos to bring to work. It’s not too messy, and it’s easy to dunk a piece of crusty bread in if you have extra lying around the kitchen.
Remove the papery outer skin from the garlic head, leaving the cloves intact. Cut 1/4 inch off the top of the head of the garlic, exposing the cloves, and drizzle with 2 teaspoons of the olive oil. Wrap in foil. Roast for 45 minutes.
Let cool Gently squeeze the roasted garlic cloves out of the papery skins into a small bowl and set aside.
While the garlic roasts, in a large pot, heat the remaining 3 teaspoons olive oil over medium heat. Add the onions, leeks, and shallot and cook, stirring often, for 30 minutes.
Add 1/2 teaspoon of the salt, the thyme, and the sage. Cook, stirring often so the onions do not burn, for 30 minutes, until the onions are a dark golden color.
Stir in the flour and cook for 1 minute. Add the broth and wine and bring to a boil. Reduce the heat to low and simmer for 30 minutes.
Combine the roasted garlic, remaining 1/2 teaspoon salt, and the cooked onion mixture in a blender. Puree until smooth.
Pour the pureed onion mixture back into the pot and add the cream. Simmer over low heat for 8 to 10 minutes until heated.
Ladle into bowls, garnish with thyme leaves, and serve.
