1. Preheat oven to 375°F (190°C). 2. In a small bowl, mix 10g ground flaxseed with 30ml water. Let sit for 5 minutes to form a gel. 3. Heat 5ml olive oil in a skillet over medium heat. 4. Add 50g diced onion, 50g grated carrot, and 30g diced celery. Cook until softened, about 5 minutes. 5. Add 6g minced garlic and cook for 30 seconds. 6. In a food processor, pulse 30g walnuts until finely chopped. 7. In a large bowl, combine 150g cooked brown lentils (slightly mashed), chopped walnuts, sautéed vegetables, 30g breadcrumbs, the flaxseed gel, 15g ketchup, 5ml Worcestershire sauce, 5g Dijon mustard, 1g dried thyme, 1g dried sage, 2g salt, and 1g black pepper. 8. Press the mixture into a small loaf pan lined with parchment paper. 9. Spread remaining 15g ketchup on top. 10. Bake for 30-35 minutes until firm and lightly browned. 11. Let cool for 10 minutes before slicing and serving.