Preheat your waffle iron according to manufacturer's directions. Put mashed sweet potatoes in a mixing bowl and mix in eggs one at a time. In a separate bowl combine flour, cornmeal, baking soda and salt; mix thoroughly. Add half the dry mixture to the sweet potato mixture and mix with a spoon. Add melted butter and half of the buttermilk. Mix again thoroughly. Repeat with remaining dry ingredients, then buttermilk. Mix into a batter. If the batter is too loose, add additional flour until you have a nice thick batter. Drop ¼–½ cup of the batter onto your hot waffle iron and cook approximately 10 minutes or until golden brown. Top the waffles with pan-grilled leftover holiday ham and a small handful of fresh arugula, then top with a freshly poached egg or two.