Soak the red lentils in plenty of water for 3 hours
Drain them well in a sieve
Preheat the oven to 175°C fan and line a loaf tin with parchment paper or lightly grease it
Place the drained lentils in a blender with the eggs, salt, baking powder and neutral oil
Blend until you have a smooth, thick batter with no visible lentils
Finely chop the mozzarella and roughly chop the fresh spinach
Fold the mozzarella and spinach into the batter until evenly distributed
Pour the mixture into the prepared loaf tin and smooth the top
Bake for about 45 minutes, until the loaf is golden and feels firm in the centre
Allow to cool in the tin for 10–15 minutes, then lift out and cool further before slicing into 14 pieces