How to Make It
Preheat the oven to 450°. On a baking sheet, toss the carrots with 2 tablespoons of the olive oil and roast until tender, about 30 minutes. Scrape into a large serving bowl.
Meanwhile, in a small saucepan of boiling water, cook the lentils until al dente, about 15 minutes. Drain well.
Add the lentils to the carrots along with the cucumber, dill and 2 tablespoons of the oil; season with salt and pepper.
In a blender, puree the feta with 2 tablespoons of water and the remaining 3 tablespoons of oil until smooth. Season with salt. Spoon the dressing over the lentil salad and serve.