Spicy Thai Shrimp Soup

heat oil in a saucepot, over a medium flame add ginger and chiles heat and stir for 30 seconds add stock and lime zest bring to a boil, add rice cover, reduce heat, and simmer for 20 minutes add shrimp, mushrooms, coconut milk, and onions simmer for 4-5 minutes, just until shrimp are cooked remove from heat and stir in lime juice spoon into small bowls garnish with scallions serve hot