In a dry wok or pan over low heat, toast the rice grains, stirring continuously until they turn golden and fragrant, about 10 minutes. Grind to a coarse powder in a mortar & pestle or food processor (a few pulses will do). Set aside.
Place your wok back over high heat until smoking. Add the oil and the mushrooms. Stir-fry until the mushrooms are browned on the edges.
Add the toasted rice powder, sugar, fish sauce (or vegan fish sauce), soy sauce (if needed), and lime juice.
Stir-fry for another minute, and then add the chili, shallots, scallions, cilantro, and mint. Stir-fry for one more minute, then taste for seasoning, adding more chili, sugar, fish sauce, and/or lime juice to your taste if needed.
Serve with sticky rice, steamed jasmine rice, and/or lettuce leaves.