Cut chicken into strips (optional: soak in soy sauce for one hour). Fry chicken in butter and garlic until brown. Reduce heat and simmer until done. Cool in the refrigerator. Toss cooled chicken with coriander, sesame seeds and scallions. Toss in sesame dressing (see below). Serve over a bed of shredded lettuce. DRESSING: Make a paste of mustard and water. Blend in other ingredients until homogeneous. Optional: let dressing sit at room temperature over night to get well-blended mixture (but it tastes fine freshly made, too)