Combine lentils, water, and the rest of the ingredients (except for the stuffing, seasonings and ketchup) in a large sauce pan. Bring to a boil, cover, reduce the heat to a simmer and let cook about 30 minutes or until the majority of the water is absorbed.
Remove from heat, add in egg and seasonings, then slowly add in stuffing until you get a thick consistency.
Transfer mix to an oil sprayed loaf pan, spread ketchup on top, and place in the oven on the middle rack for 30 minutes uncovered.
Let rest for 30 minutes before serving. Slice and enjoy.