Start your broth: In a medium pot, pour in the vegetable broth, a few wedges of lemongrass, and a thumb or two of sliced galangal or ginger. Let that simmer gently—this is where all the flavor starts building.
Prep your veggies + tofu: While the broth is doing its thing, open your canned veggies (don’t drain everything—you want a little of that mushroom flavor in there!). Cut your tofu into small cubes. Silken tofu is super delicate, so be gentle.
Add the magic: Once your broth is nice and aromatic, add in: 1 full can of straw mushrooms (I use the whole can because I’m obsessed with them), 1/2 can of bamboo shoots, 1/2 can of sliced water chestnuts, and 1 1/2 tablespoons of the tom yum paste, Let it come to a gentle boil so the flavors really mix together.
Finish it off: Right before turning off the heat, add the cubed silken tofu. It’ll warm through in the hot broth. You can also squeeze in half a lime here if you like that extra sour kick (I do!).
Serve + enjoy: Ladle the soup into bowls, top with a little fresh cilantro, and serve hot. If you want something more filling, you can pour this over white rice or cooked rice noodles—it’s SO good.