Rinse the lentils and combine them with the water and a pinch of salt in a pot over medium high heat. Bring the water to a boil, then lower it to a simmer and cook the lentils (uncovered) for about 15 to 20 minutes until they are cooked through, but still have a bit of bite to them. Drain the lentils, rinse them under cold water, then set them aside to continue draining until you need them.
In a large bowl, toss together the lentils with the cider vinegar, lemon juice, olive oil (if using), and a good pinch of salt. Add in the remaining ingredients and toss to combine. Taste for seasoning and adjust if necessary. Makes 4 to 6 servings.