Method
Shell, de-vein, and clean shrimp; clean and reserve shells. Place shells in a large pot with sesame oil.
Cook shells for 3 minutes until they change color; add water and simmer for 15 minutes. Remove shells; reserve water.
Add chicken base to water, sweet and sour sauce, garlic, ginger, shallots, and mushrooms. Adjust taste with additional water, if needed. Gently simmer 5 to 10 minutes.
Add shrimp and cook to tender. Finish soup when serving with remaining ingredients.