Make the nam jim jaew sauce: In a small bowl, whisk together the fish sauce, lime juice, seasoning sauce, sugar, chile flakes, garlic, and ginger until the sugar is fully dissolved. Set aside.

Make the toasted rice powder: In a medium skillet over medium-high heat, toast the rice, stirring continuously, until the grains are light brown, about 10 minutes. Turn the heat to low and continue cooking, stirring occasionally, until the grains are golden brown, about 10 minutes more. Transfer to a small bowl and set aside to cool.

Using a mortar and pestle or spice grinder, grind the toasted rice into a coarse powder. Set aside or store in an airtight container at room temperature for up to 1 month.

Make the meatballs: In a medium bowl, use a silicone spatula or your hands to stir together the pork, cilantro, lemongrass, onion, lime juice, makrut lime leaves, rice flour, chicken bouillon, fish sauce, sugar, salt, and 1 tablespoon of the toasted rice powder until evenly incorporated. Set aside for 15 minutes.

Line two baking sheets with parchment. Position a rack in the center of the oven and preheat to 350°F. Using a tablespoon, scoop the pork mixture, shape into tightly pressed balls (about 1 ounce each), and transfer to a prepared baking sheet. Into a medium pot fitted with a deep-fry thermometer, pour the oil to a depth of 2 inches and turn the heat to medium-high. When the temperature reads 325°F, gently add a few meatballs (do not crowd the pot) and fry until the exteriors are slightly crispy, about 2 minutes. Transfer to the second prepared baking sheet, spacing about 1 inch apart. Repeat with the remaining meatballs.

Bake until the meatballs are fully cooked, about 5 minutes. Transfer to a platter, garnish with the cilantro, mint, onion, and peanuts, and serve warm with the lettuce and nam jim jaew sauce on the side.