Cha-om is a shrub-like plant comprised of long branching stems covered with many small and slender bi-pinnate leaves. The dark green leaves are narrow, oblong to oval, and have a feathery appearance, similar to a fern. Generally, cha-om is harvested for its young, tender, and crisp leaves. The leaves are attached to woody stalks, and the fibrous dark green branches are covered in sharp, spiny thorns that become larger with maturity. The plant also produces small yellow flowers seasonally. Cha-om has an odiferous scent when raw, often likened to a musty, sulfuric, and metallic, unpleasant smell. The smell is reduced when the leaves are cooked, and the leaves soften into a crisp and succulent consistency with a vegetal, subtly bitter, herbaceous, and nutty flavor.
Cha-om is a good source of vitamin A to maintain healthy organ functioning; calcium and phosphorus to protect bones and teeth; vitamin C to strengthen the immune system; and iron to develop the protein hemoglobin to transport oxygen through the bloodstream. The herb also provides fiber to regulate the digestive tract and B vitamins to promote optimal cell functioning. In natural, eastern medicine, cha-om is boiled and consumed to soothe digestive issues and stomach pain.
The leaves of cha-om can be consumed raw, but the offensive odor of the fresh leaves is generally off-putting. The leaves are most commonly cooked to reduce the smell and are popularly stir-fried, boiled, fried, or sauteed. Cha-om is utilized similarly to herbs as a flavoring agent and can be incorporated into salads, curries, soups, stir-fries, noodle-based dishes, or mixed into rice. In Thailand, the leaves are traditionally cooked in egg-based dishes, similar to omelets, frittatas, or egg casseroles. Cha-om pairs well with fruits such as papaya and mango; aromatics including chile peppers, ginger, garlic, and scallions; meats such as beef, pork, and poultry; seafood including shrimp and fish; carrots, radish, and eggplant. Fresh cha-om will keep for up to one week when stored unwashed in the refrigerator. The leaves can also be frozen for extended use.
Cha-om is available year-round in tropical climates. In cooler regions, the young leaves are typically harvested in the spring through summer.