Made from segments of pomelo, a large, grapefruit-like citrus fruit, that have been just barely bruised with lemongrass, chili, eggplant, and seasonings including naam puu (northern Thai–style crab paste), there’s a lot going on in tam som oh. Indeed, it’s the epitome of a Thai dish, both in that it features a variety of different flavors and that these flavors are subject to personal preference. If you like spicy, throw in a couple extra chiles. If you don’t like unfiltered fish sauce, you don’t need to include it.
When making this dish, choose a pomelo that is slightly on the tart side, and note that an unpeeled pomelo weighing four pounds will produce approximately two pounds of flesh. Be sure to use the black, northern, Thai-style crab paste, not the stuff of the same name that often includes oil and chiles.
Adapted from Austin Bush’s book, The Food of Northern Thailand (Clarkson Potter Publishers., 2018)
In between bites “clear their palate” by nibbling on the herbs or cabbage.
What You Will Need
- 2 tbsp. (½ oz.) dried shrimp
- 1 medium (4 lb.) pomelo
- 8 small fresh red Thai chiles, stemmed
- 3-4 medium stalks fresh lemongrass (3½ oz.) outer layers peeled, green section discarded, pale section thinly sliced (¼ cup)
- 1-2 tsp. Northern Thai-style black crab paste (naam puu)
- 1 tbsp. unfiltered fish sauce (plaa raa)
- 1 tbsp. palm sugar (optional)
- 2-3 small Thai eggplants (3 oz.), stemmed, halved, and thinly sliced (once cut, keep in a bowl of water with a squeeze of lime to prevent them from browning)
- 1-2 tsp. fresh lime juice, or more as needed
- 2 cups assorted fresh vegetables and whole herbs, such as napa cabbage, wild betel leaf and sawtooth cilantro, for serving
- Steamed Thai sticky rice, for serving
- In a wok or large skillet set over low heat, add the shrimp and cook, stirring occasionally, until fragrant and uniformly toasted, about 5 minutes. Transfer to a small bowl and set aside.
- Use a knife to peel the rind and pith of the pomelo and discard. Pull the fruit into segments, pulling out and discarding any seeds and as much interior pith as possible. Measure approximately 1¾ cup (14 oz.) of the fruit, reserving the rest for another use.
- In a clay mortar, add the chiles, lemongrass, ½ teaspoon of the black crab paste, the fish sauce, lime juice, and palm sugar (if using). Using the pestle and a large spoon, pound and mix the mixture to a coarse paste. Add the toasted, dried shrimp and drained eggplant pieces, pounding and mixing until just bruised and combined. Add the pomelo segments, mixing lightly so they stay in big chunks and do not get completely crushed. Taste and adjust the seasoning, adding more crab paste or lime juice as needed; Tam Som Oh should taste funky, herbal, spicy, tart, and sweet (in that order).
- Transfer the salad to a serving plate. Serve with the vegetable and herb sides and some sticky rice as part of a Northern Thai meal. For an authentic experience, eat this dish by hand, taking a little piece of the rice, rolling it in a ball and then scooping some of the pomelo salad.