Preheat oven to 400°F.
Cut garlic bulb on its equator (or take 10 loose garlic cloves), wrap in foil with a drizzle of olive oil and salt and pepper. Roast in preheated oven for 30to 40 minutes. Allow to cool before squeezing garlic cloves out.
While garlic is roasting, slice 8 – 12 bacon slices into bits and fry in a pan until crispy. Alternatively, roast the garlic and make the bacon bits ahead of time.
Melt butter in a stock pot or Dutch oven. Add mirepoix mixture and sauté until soft,about 5 or 6 minutes.
Add sliced mushrooms, salt, pepper, thyme, and parsley and sauté until the mushrooms are soft (maybe less time if you’ve pre-cooked the mushrooms). Once cooked,reserve a few spoonfuls of the mushrooms and veggies.
(Optional) Add a splash of white wine or sherry.
Add roasted garlic and chicken stock to the pot. Bring to a boil and reduce to a simmer, cooking for 30 minutes.
Remove from the heat and stir in the cream. Alternatively, if you plan on freezing the soup, maybe don’t add it until soup has been thawed and reheated, or else you could bring a split frozen-and-thawed cream back together with a roux sometimes.
Use immersion blender and/or regular blender to blend the soup until smooth. If using regular blender, work in batches to avoid overfilling, and start the blender off with small pulses or on low.
Return blended soup to pot and add more salt and pepper to taste.
Serve garnished with reserved mushrooms and veggies, bacon bits, and chopped parsley.