Preheat your oven to 400 F.
Cut carrots in half lengthwise. Slice them into pieces about 4 inches long. Toss them with a tablespoon of the olive oil and then place them onto a parchment or foil lined baking sheet. Sprinkle them with sea salt and black pepper and bake for about 30 minutes, or until they're gently caramelized.
Whisk the remaining two tablespoons of olive oil with the lemon juice and additional salt and pepper to taste. Dress the arugula with the dressing.
Divide the arugula onto three or four plates. Top each bed of arugula with even portions of the carrots and avocado, and then sprinkle the lentils on top. Serve.