- Heat olive oil and butter in a deep non-stick pan. Add garlic sauté till fragrant. Add onions and sauté till it turns translucent. Add thyme leaves and flour, mix well and sauté for a minute. Add button mushrooms, shiitake mushrooms and salt, mix well, cover and cook for 5-6 minutes. Add morel mushrooms with the water and mix well. Add salt and mix. Remove from heat and blend with a hand blender. Add water as required and blend to a smooth puree. Strain the puree into another non-stick pan. Heat the strained puree, add milk, mix well and cook for 5-6 minutes. Add cream and crushed peppercorns, mix well and simmer for 2 minutes. Drizzle cream, sprinkle crushed peppercorns and serve hot.