
Simmer the lentils in 2.5 cups water for 25 minutes until soft; drain. Mix the flaxseed with 5 tbsp water and let it thicken.
Heat oven to 375°F. Sauté the finely diced onion, grated carrot and garlic in 1 tbsp oil for 6 minutes.
Mash two-thirds of the lentils, then mix all lentils with the vegetables, oats, flax mixture, soy sauce, 2 tbsp ketchup, salt and pepper.
Press into a parchment-lined loaf pan, spread the remaining ketchup on top, and bake 45 minutes. Rest 10 minutes before slicing.
While it bakes, boil the cubed potatoes 15 minutes, drain, and mash with the oat milk, remaining oil and salt.
Slice the loaf and serve with mashed potatoes. It slices even better the next day, so it's a great make-ahead.
Photo: DinnerDrop