Heat oil in a saucepan, when hot add chopped onions and garlic and cook until soft. Mix in curry powder and cayenne pepper - NOTE: don't add cayenne pepper if you don't like it spicey.

Add in beef and cook for 5-10 minutes until cooked. Add chopped tomatoes and lentils and simmer on a medium-low heat for 20 minutes.

Serve on brown rice with a dollop of yogurt and sprinkle with cashew nuts.