Rinse dried lentils and place in large sauce pan and cover lentils about 2 inches above beans.
Bring to boil then reduce heat to medium.
Cook about 20 minutes until tender, making sure to check water as to not let them dry out.
Remove from heat, drain, rinse and place in large mixing bowl.
Add diced cucumber, chopped red onion, sliced grape tomatoes, capers and salt and pepper to taste.
Meanwhile in small bowl combine olive oil, lemon juice, vinegar, minced garlic, and mustard and whisk together.
Pour dressing over salad and mix well.
Can top with cilantro.
Cover and store in fridge for up to five days.