Rinse the red lentils under running water than place into a large bowl, cover with water and leave to soak for at least 2 hours.
Pre-heat the oven to 200°C. Line a 2lb baking tin with non-stick baking paper.
Drain the soaked lentils and place in a food processor with the water. Blend until smooth then pour into a large bowl.
Add the gram flour, ground flaxseed, salt, baking powder and psyllium husk. Stir together to combine then add the mixed seeds and lemon juice. Stir again, making sure everything is well combined.
Pour the mix into the prepared loaf tin and tap it on the work top. Sprinkle the extra seeds on top, gently pressing them into the mix.
Place in the middle of the oven and bake for 40-45 minutes until the top is lightly browned and skewer comes out clean.
Transfer to a cooling rack and leave to cool fully before slicing.