Thinly slice the onion and red pepper.
Cut the tofu into 2cm cubes. Cut the courgette into small pieces.
Heat some oil in a non-stick frying pan then fry the tofu cubes until crispy and golden all over. Transfer them to a plate.
Add more oil to the pan, then stir-fry the onion and red pepper for 5 minutes, then add the courgette and keep stir-frying for a couple of minutes.
Add the vinegar and slightly caramelise the vegetables. Add the drained lentils and a dash of water.
Stir in the mustard.
Stir until the lentils are creamy and have warmed through.
Fold in the tofu gently, then the parsley and the minced garlic.
Serve warm.