Saute the onion, carrot and garlic in the olive oil until softened.
Add the lentils and spices and stir until well combined.
Add the stock and lemon juice. Stir well. Cover with lid. For instant pot: press soup function and 15 minutes, high pressure. For stove top: Cover and bring to a gentle simmer until lentils are tender +- (30 minutes).
Now, add chopped parsley, black pepper and salt. Season once more to taste. If a thinner soup is preferred, add more stock.
Serve in heated bowls. Drizzle with olive oil and garnish with lemon slices and fresh herbs.