Heat the oil in a wok or skillet on medium-high heat. Add garlic, shallots, lemongrass, and chili; stir-fry until fragrant, about 30 seconds. Add pork and stir-fry, while breaking it up with a wooden spoon until cooked through, about 5–6 minutes. Stir in the chicken stock, fish sauce, lime juice, and palm sugar and bring to a boil. Remove from heat and let stand 10 minutes.