Prepare Chicken: Trim excess fat from chicken; remove wing tips. Mix mixture for skin; rub chicken inside & out with it. Leave uncovered at room temperature, while coating is absorbed and dried. Repeat if necessary. Stuffing: In hot wok, heat peanut oil to smoking. Stir-fry ground pork 2 minutes; add mustard green, ginger & sugar; stir-fry 1 more minute. Remove & cool. Lotus Leaves: Number of leaves depends on their size & that of chicken. Reduce heat under boiling water to simmer, & steep leaves for 3-5 minutes, until wet through & pliable (no longer or leaves may shred). Now soak in cold water for 10 minutes, or longer, until time to use them; open folded leaves in cold water to wash them. Wrap Chicken: Preheat oven to 550 degrees. Stuff chicken with pork mixture. Cut hard center out of lotus leaves, then slit along fold about 8 cm on each side of center, so cut away center can be overlapped. Wrap chicken in 3 layers of lotus leaves. Tie securely with piece of cotton or fiber string (don't use nylon; it might melt). Spread soft, wet modeling clay about 1 cm thick on sheet of newspaper. Bring clay pack around chicken & seal. Remove newspaper. (Use foil if clay unavailable.) Roasting: Place clay-covered chicken on rack in shallow roasting pan in preheated oven. Bake for 1 hour; reduce heat to 350 degrees & bake for another 1.5 hours. Serve: Present fired clay chicken to table. Crack clay with suitable object, allowing some of steam to escape before you proceed. Remove clay; carefully cut open lotus leaves with scissors. Chicken will be very soft & tender; break apart to get at stuffing. Serve guests, or invite them to pick with chopsticks.