Betül's red lentil soup (mercimek çorbası)

Red lentil soup is an old standby here.  Almost every Turkish restaurant serves it, and it's usually good, so it's a staple in the diets of many of us.  Many of the students agree that the best lentil soup they had while they were here was made by Betül.  Fortunately I had some time to cook with her on Friday, so I'm giving you my estimation of her recipe.  I made it last night and needed to add a little more water so I'm adjusting that, but otherwise it worked well.

250 g red lentils
1 small onion
4 Tablespoons extra virgin olive oil
2-3 T tomato paste or 3-4 fresh tomatoes
4 cups boiling water
3 tsp salt
black pepper to taste
red pepper (pul biber) to taste
dried mint to taste

Put the lentils in a bowl with water and soak for about 10-15 minutes.  Put oil into a large saucepan and heat.  Finely dice the onion and cook in the oil.  Once the onions are cooked, add either tomato paste or finely diced tomatoes.  Cook for a few more minutes.  Drain the water from the lentils and put the lentils into the pot.  Stir.  Add boiling water.  Bring the pot back to boiling, stirring frequently.  Add salt, black pepper, red pepper, and mint.  Cook for about 1/2 hour until the lentils are starting to get mushy and fall apart.  At this point you can either blend the soup with a hand blender if you want a smooth soup or serve as is.  Serve with sliced lemon (it's excellent with lemon juice squeezed into it) and red pepper for people to add if they like the soup more spicy.