Cut the top off the pumpkin to make a lid. Scoop out the seeds and stringy pulp. Sprinkle salt and pepper inside. Set aside.
Start to brown sausage in a saute pan. Add chopped onion, and saute until it is soft and the meat is browned, but not cooked through.
Add rice and lentils, stir around to coat with any fat in the pan, and brown lightly. Add water, bring to a boil. Lower to a simmer, cover, and cook 45 minutes until done.
Fill pumpkin lightly with stuffing and place in a baking pan. (Any extra stuffing can be placed around the pumpkin in the pan.) Bake in a 400 oven for 45 minutes.
Serve, scooping out spoons full of both pumpkin and stuffing together.