Heat up a tbsp of olive oil in a saucepan then saute the onions and garlic for 2 or 3 minutes, until the onions go transparent and slightly browning.
Add the tomato puree, spices and chili flakes, and season with salt and pepper. Fry for a further 2 mins. Add a splash of the vegetable stock if the mixture starts to stick to the pan.
Mix in the potatoes and the vegetable stock. Bring to a simmer and cook for about 10 minutes.
Add the cooked lentils and simmer for a further 5 to 10 minutes, until the potatoes are soft.
Turn off the heat and allow to cool slightly.
Use a hand blender to puree the mixture to your desired consistency. Let the soup sit for 5 minutes before serving.
Serve with fresh lemon juice, a drizzle of olive oil and a sprinkle of chile flakes.
Serve with the sautéed vegan sausage on top for crunch and texture (optional)