Step 1

Heat oil or butter in a large, heavy-bottom pot or dutch oven. Add onion and saute over medium-high heat, 3-4 minutes, stirring constantly until golden and fragrant. Lower heat to medium, add garlic, saute 2 minutes.

Step 2

Add the sliced mushrooms, salt and rosemary. Saute 10-12 minutes, stirring occasionally, taking your time here, allowing mushrooms to release all their liquid. Add the cooking sherry (do not mistake this for sherry vinegar).  Turn the heat up, and cook this completely off, stirring until most or all of the liquid in the pan has cooked off about 3-4 minutes, and mushrooms glisten.  Optional: Set aside 1/4 cup mushrooms for garnish.

Step 3

Turn the heat back down to medium, sprinkle the flour over top, stir constantly, toasting it for 1-2 minutes. Add one cup of hot stock and stir it in WELL, getting all those browned bits (in corners and bottom) mixed in. (A wood spoon works well here.) Add the second cup of stock, stirring well to combine, then add the third cup of stock and bring it to a gentle simmer, whisking. It will thicken.

Step 4

Stir in the sour cream until fully incorporated.

Step 5

Season with pepper and taste for salt.

Step 6

If you would like a thinner soup, add a little more broth, readjusting the salt.

Step 7

, thinly slice garlic (the long ways). Heat 2 tablespoons oil in a little saute pan over medium heat. Add the garlic slices, not overlapping, sprinkle with a little salt, and turn over when golden, about 3 minutes.  Cook other side until golden and crispy. Set on a paper towel. At the same time you could toss in a few more rosemary leaves.

Step 8

Ladle in bowls and top with a few slices of mushrooms and garlic chips and a drizzle of truffle oil. Serve with crusty bread.