Step 1In a bowl, stir the doubanjiang, chile oil, ginger and black vinegar with 1 tablespoon of water. Set aside.
Step 2In another bowl, combine the sugar, mirin, rice vinegar and salt. Set aside.
Step 3Cook the rice in a rice cooker according to the manufacturer's instructions. Alternatively, in a small saucepan, combine the rice with 1¼ cups of cold water and bring to a boil over high heat. Cover and simmer over low heat until the water is absorbed, 15 minutes. Remove from the heat and let stand, covered, for 10 minutes.
Step 4Transfer 1 cup of the hot, cooked rice to a small bowl; reserve the rest for another use. While the rice is still hot, sprinkle the sugar, mirin, rice vinegar mixture over the rice and using a wooden paddle, mix to blend. While the rice is still warm, using wet hands, form the rice into 24 loosely packed 1/2-inch balls.
Step 5Arrange the 24 lettuce leaves on a platter.
Step 6In a large nonstick skillet, heat the oil over medium heat. Add the rice balls and cook, turning, until crispy all over, about 12 minutes.
Step 7Wrap a slice of lardo around each warm rice ball and set in a lettuce cup. Top each with a lobe of sea urchin and dab with the doubanjiang sauce. Garnish with scallions. Serve immediately.