Thai basil changes a pot of soup the moment it hits the heat. One handful can turn broth from pleasant to fragrant, savory, and bright, with a flavor that lands somewhere between anise, mint, clove, and pepper.

Water spinach cooks so fast that it can turn a thin, plain broth into a bowl of green, garlicky comfort in minutes. The trick is knowing when to add it, how to season the broth, and how to keep those hollow stems tender instead of soggy.