- Cook the Lentils the day before: If using dry lentils, simmer until tender (about 20 minutes), then drain. You’ll want the lentils to be fully cooked, so they almost fall apart when squeezed between your fingers. Store for later.
- Sauté the Veggies: Heat olive oil in a skillet. Add onion and cook 5–7 minutes until the onions are slightly translucent. Turn up the heat to high and add in mushrooms and carrots, cook until soft and most liquid evaporates, 5-6 minutes over medium-high heat.
- Mix the base: In a large bowl, combine lentils, sautéed veggies, breadcrumbs, flaxseed, egg, tomato paste, 1 tbsp vinegar, and spices. Mash lightly with a fork, a potato masher, or have fun and mix well with your clean hands until mixture holds together but still has texture.
- Shape and Bake: Preheat oven to 375°F. Line a loaf pan with parchment. Press mixture firmly into the pan.
- Make Glaze: Mix until well blended 1/2 cup ketchup, 1 tbsp apple cider vinegar, 1 tsp maple syrup, 1/4 tsp smoked paprika and spread evenly over the loaf.
- Bake 45–50 minutes until firm and edges crisp slightly. Let cool for 20 minutes before slicing to help it set.