On the streets of Jakarta and elsewhere in Indonesia, some vendors’ pushcarts are essentially mobile salad bars, where bespoke vegetarian compositions of greens, sprouts, shredded cabbage, fried potatoes and tofu, hard-cooked eggs, shrimp chips, and more are dressed in a spicy and aromatic peanut sauce. The dish these hawkers are making, gado-gado, is true to its name, which means “potpourri.” The salad lends itself to creativity; nearly any combination of raw and cooked vegetables, along with rice or thin noodles, if you like, can be used