Instructions

  1. Preheat oven to 350°F.
  2. Combine water, lentils, and 1/4 teaspoon salt in a large saucepan. Bring to a boil and cover the pot, reducing the heat to medium-low. Simmer for 20 minutes (lentils will not be fully cooked). Drain lentils in a colander over a bowl, reserving 1 cup cooking liquid.
  3. Combine lentils and diced onion in large covered casserole dish. Combine 1/4 teaspoon salt, reserved cooking liquid, ketchup, and seasonings. Pour the liquid mixture over the lentil mixture, stirring to combine.
  4. Bake at 350°F for 1 hour.