Mash the Lentils:Place cooked lentils in a large bowl and mash about half of them with a fork or potato masher (leave some whole for texture).
Combine Ingredients:Add onion, carrot, garlic, oats/breadcrumbs, egg (or egg substitute), tomato paste, cumin, paprika, herbs, salt, and pepper. Mix well until the mixture holds together. If too wet, add more oats/breadcrumbs; if too dry, add a splash of water or a little olive oil.
Shape Patties:With damp hands, shape the mixture into 4–6 burger patties.
Cook:Heat a little olive oil in a non-stick pan over medium heat. Cook patties for 4–5 minutes on each side, until golden brown and heated through.
Serve:Serve in burger buns with lettuce, tomato, onion, and your favourite sauces or toppings.