Preheat oven to 400. Toss cauliflower, carrots, leek or onion, and tomatoes with olive oil and season with salt and pepper. Pour into a roasting pan and roast for 20-30 minutes or until the veggies are just tender (not mushy!).
Meanwhile, cover the lentils with water in a medium saucepan. Add the chicken base to the pot. Simmer the lentils for 25-30 minutes or until the lentils are just tender (not mushy!). Drain and set aside.
Whisk the dressing ingredients together in a small bowl. Taste and adjust vinegar and oil to your taste.
Toss together the lentils, veggies, cooked chicken and dressing. Taste and add salt and pepper if needed. Serve warm or room temperature and top with crumbled goat cheese or feta.