If using raw lentil, cook it first so it becomes very soft (about 20 minutes).
Peel and chop the onion, garlic and carrot into small pieces. Also cut the peppers into small cubes.
Put 160 ml of water, garlic, onion, carrots and peppers in a pan, cover and cook on medium heat until all the vegetables are soft.
When you have the lentils and vegetables ready, put all of the ingredients for the filling in a mixer and mix quickly. It is best to use pulse option so that the ingredients are mixed but still remain in smaller pieces.
Coat the puff pastry with barbecue sauce and place the filling in a straight line in the middle.
Cover the filling with the dough from both sides and turn over on the baking sheet.
Use a sharp knife to cut the lines at the top.
Bake for 30 minutes at 200°C. Wait a few minutes for it to cool a bit and become more compact before taking it out of the pan. Then slice it and serve.