1 cup lentils
2 tbsp butter or vegetable oil
Pick lentils over, wash, add 2 cups of cold water and soak for 3-4 hours. Drain soaking water, cover lentils with fresh water and bring to boil. Season with salt just before the end of cooking. Lentils are cooked when its grains are soft. Drain all remaining water and dress lentils with butter.
Lentils could be dressed with browned onions. Finely slice 1 medium onion and brown it in a small quantity of butter(oil), remaining butter add directly to lentils.
Lentils with tomato paste and onions is cooked according to above instructions, just add 3-4 tbsp of tomato paste to fried onions and fry a little bit longer. For lentils with sour cream and onions add 1/2 cup of sour cream to onions and bring to simmer.