Wash well the lentils. Put lentils in a large pot and cover with water and boil. As soon as the water comes to boil take the pot off the heat and empty contents to a drainer and wash the lentils again. This is done to get rid of the black water of the lentils.
Wash the pot if necessary. Put the lentils back into the pot again. Add about 1 litre of hot water. Cook to boil from start.
When the water with lentils come to boil add bulgur and salt. Continue to cook.
If unpleasent foams come up again on top of the pot, skim and and discard.
When the lentils are half ready add the noodles.
Cook for about 6 minutes more, stirring occasionally, until the noodles are done and close the heat.
Also add the chicken stock/bullion - if you choose to use - when you are adding the noodles.
Meanwhile if the soup turns too thick, add more hot water if you want.
Meanwhile chop well the onions and crush the garlic. Heat the olive oil in an another pot over medium heat. Add first the onions and saute until cooked. Then add the garlic. Cook, for another 2 minutes.
Add the tomato paste to the onions and cook, stirring, for 2 more minutes.
Pour the onion mix to the lentil soup pot.
In the pan you prepared the onions melt the butter. Add red pepper flakes and mint into it. Garnish the soup with this butter mixture.