Heat vegetable oil in heavy large saucepan over medium-low heat. Add minced onion and garlic and saute until onion is tender, about 8 minutes. Increase heat to high. Add all mushrooms and thyme and saute until mushrooms release their liquid, about 5 minutes. Add chicken stock and bring to boil. Reduce heat, cover and simmer 20 minutes. (Can be prepared 1 day ahead. Cover and refrigerate. Bring to simmer before continuing.) Add spinach and parsley to soup and stir until wilted. Season soup to taste with salt and pepper. Ladle into bowls and serve. SOUP 65