Preheat oven to 425 degrees and line two sheet trays with nonstick foil.

Scatter sliced mushrooms, whole garlic cloves and thyme on the two lined sheet trays. Toss with olive oil and season with salt and pepper.

Roast for about 15 mins until golden brown.

While mushrooms are roasting, place a medium pot on the stove over medium heat and add the butter.

Add the shallots to the melted butter, season with salt and pepper and cook until golden, stirring frequently.

Remove the mushrooms from the oven, discard thyme sprigs and squeeze the garlic out of the peels. Reserve 1/2 cup mushrooms and add the remaining mushrooms and garlic to the pot.

Add sherry and cook until slightly reduced, about 2-3 mins.

Add the stock, season with salt and pepper and bring to a boil, then reduce to a simmer and cook 15 mins.

Puree using an immersion blender or in a blender in batches until smooth. Add 1 tsp of thyme and the cream if using and stir well to combine. Season to taste.

Ladle into bowls and top with a spoon of the reserved mushrooms.