Thai Hot-and-Sour Shrimp Soup

Ingredients: 20 cups water 6 tbsp chicken Bovril 1/2 Spanish onion coarsely chopped (or 1 cup chopped green onions) 1 tbsp (or to taste) hot pepper sauce 1 tbsp soya sauce 1 lb frozen cooked shrimp 2 tbsp chopped cilantro 1 tsp grated lemon rind 1 1/2 tbsp fresh lemon juice or lime juice optional:…