To make basic Thai basic seasoning paste – Kratiem Prik Thai, place garlic, black pepper and cilantro root or stem in a mortar with pestle and pound until it becomes a fine paste. Gently stir in soy sauce and salt.
Heat a wok on a high heat and pour in a high-heat cooking oil such as peanut oil or canola oil. Stir-fry ground meat with Thai basic seasoning paste until it is fragrant and almost cooked through—about one minute.
Stir in diced celery, sweet pepper and apple and continue until the pork is cooked—about three minutes. Set aside.
While waiting for the filling to cool down, prepare garnish with 24 mini bell pepper rings and 24 cilantro leaves with some stem attached.
Before serving, spoon the filling into the cups and garnish with cilantro and sweet pepper.