Mustard and Collard Greens

Place ham hocks in large saucepot or dutch oven;cover with water and cook,covered, over moderately low heat for 2 hours. while ham is cooking, remove stems from greens and tear leaves into fairly large pieces. rinse greens several times in warm, salted water; drain well. stir sugar, salt and pepper into water with ham hocks. add enough greens to fill pot; cover and when greens shrink, add more, stirring occasionally, until all the greens are added. cook greens for 1 1/2 to 2 1/2 hours, depending on the tenderness of the greens. remove the meat from the ham hocks and serve with greens. serves 8. [greens may be prepared a day ahead and reheated just before dinner.]