Spread a thin layer of hogao down the center of each pork slice. Top with a slice of beef.
Roll tightly and tie with kitchen string. Set a steamer basket in a medium pot filled with the beef stock. Arrange the beef rolls in the steamer. Bring the stock to a boil over medium-high heat, cover and steam for about 40 minutes.In a small bowl combine the batter ingredients, except the oil.
Mix well.In a large frying pan, heat vegetable oil to 375 degrees F. Dip cooked beef rolls in the batterand immediately place into hot oil.Cook until golden and skim any loose pieces of batter from the oil.
Drain on paper towels.
Place on a large platter, season with salt and pepper.