First, prep lentils by placing 1/2 cup lentils and 2 cups of water in a medium-size pot. Bring to a boil and then reduce heat to low and let simmer for an additional 15 minutes. Remove from heat and drain remaining water and place in a tupperware and into the fridge to cool.
Next, prep veggies by dicing red onion, quartering cherry tomatoes, dicing cucumber, and slicing olives.
Once the lentils have cooled, mix all ingredients together and set aside.