In medium saucepan, combine water and lentils. Bring to boil. Reduce heat; cover and simmer 5 minutes. Add rice, onion and salt; mix well. Cover; simmer an additional 15 to 18 minutes or until liquid is absorbed and lentils and rice are tender. Remove from heat; cool 10 minutes.
Heat oven to 350 degrees. Grease 8x4 inch glass loaf pan. (Do NOT use metal pan). Stir 1/4 cup of sauce and remaining ingredients into lentil mixture, mashing mixture slightly while mixing. Press mixture firmly in greased pan.
Bake at 350 F for 40 to 45 minutes until top is golden brown and loaf is firm. Remove from oven; cool 10 minutes. Loosen edges with knife, if necessary; invert onto serving platter.
In small saucepan, heat remaining spaghetti sauce 3 to 4 minute or until hot. To serve, slice loaf; spoon warm sauce over each slice. 6 servings.