Wash and dry all vegetables. Peel the onion and cut it in half. Peel the carrot and slice it into medium-thick slices. Peel the garlic and cut it in half. Slice the chili and ginger. Clean the leek and cut it into smaller pieces.

In a pot, place the onion, carrot, garlic, chili, ginger, leek, juice squeezed from lime/lemon, lemongrass (fresh or dried), a few sprigs of fresh coriander or parsley, fish sauce, and soy sauce. Season with salt to taste. Adding shrimp shells to the broth while cooking will enhance the flavor. Cover with water in a ratio of about 5:1 (water:ingredients). Bring to a boil and reduce heat. Cook covered on low heat for about 30 minutes.

Strain the prepared broth.

Transfer the broth to an airtight container and use within 3-4 days.