White pepper, cilantro, and garlic should be ground into a paste in a stone mortar. Transfer it to a mixing bowl, add the oyster sauce and fish sauce, and combine thoroughly. Add the chicken, cover with plastic wrap, and marinate for no more than 12 hours in the refrigerator, but no less than 2 hours.
Preheat a deep fryer to 350 degrees. Paper towels should be used to line a baking sheet.
Put the rice flour in a medium mixing bowl. To create a smooth and loose batter, mix in the soda water. After removing the chicken from the marinade, immediately add it to the batter.
Chicken (at pieces) should be fried at a time for 5 to 6 minutes, or until golden brown and cooked through (check by cutting into a piece). Do not overcrowd the fryer as this could cause the oil's temperature to drop. Transfer to a clean mixing bowl after draining on the baking sheet lined with paper towels. The Thai charred chili jam should be added and coated. Serving