Easy Lentil Soup Recipe

I don't think I mentioned it on here, but a while ago I saw a nutritionist. I saw her for two different reasons, one to help with my energy levels and two to make sure I'm getting enough protein as I don't eat meat. We quickly established that my diet was severely lacking protein so she advised me to eat more legumes. Thankfully I like lentils so adding them into my diet hasn't been a problem.
One of my faviourite and really easy ways to eat lentils is as soup. It couldn't be easier, it takes about half an hour to make enough to last me a week.
Ingredients:
1 large onion
1 375 gram bag of red lentils (you can use green lentils but red lentils look nicer)
8 cups of vegetable stock (or chicken stock if you aren't vegetarian)
2 tablespoons of curry powder
Method:
Chop up the onion and brown in the pot with a little bit of oil. Add the lentils, curry powder and vegetable stock, stir well then cover and simmer for half an hour.
That's it. Simple, healthy and really yummy. You can substitute curry paste for the curry powder if you want something with a bit of bite, I prefer the flavor that the curry powder gives. 
This soup is really adaptable, you can add in almost anything. I've added potato, zucchini, broccoli and any other vegetables that need to be used up. 
I usually add in a tablespoon of greek yoghurt just before I eat it, to give a beautiful creamy flavor.