01 - Preheat oven to 350°F. Grease a 9x13 inch baking dish with butter.
02 - Heat sesame oil in skillet over medium heat. Cook onion, garlic, ginger, and carrot for 3–4 minutes until fragrant and softened.
03 - Add chopped shrimp and cook 2–3 minutes until pink. Stir in cabbage, soy sauce, oyster sauce, rice vinegar, salt, and pepper. Sauté 2 minutes. Cool slightly.
04 - Combine ricotta, egg, half the mozzarella, half the parmesan, and scallions in mixing bowl. Mix until smooth.
05 - Arrange 8 dumpling wrappers on dish bottom, slightly overlapping. Spread half the shrimp mixture over wrappers, then half the ricotta mixture.
06 - Add 8 more wrappers, remaining shrimp, and remaining ricotta. Top with final 8 wrappers.
07 - Pour broth evenly over layers. Sprinkle remaining mozzarella and parmesan on top.
08 - Cover with foil and bake for 30 minutes.
09 - Remove foil and bake 15–20 minutes until golden and bubbling.
10 - Let rest for 10 minutes before slicing and serving.