Carrots need enough room to roast. If the tray is packed tightly, their moisture has nowhere useful to go and you lose the contrast between a soft middle and a darker edge.
Cut 500 g carrots into similar-sized batons, toss with a tablespoon of oil, and spread on a tray. Roast at 210°C / 410°F for about 25–35 minutes, turning once, until tender and browned in places.
Meanwhile, warm 300 g cooked green or brown lentils. Whisk a tablespoon of lemon juice with two tablespoons olive oil and half a teaspoon mustard. Dress the warm lentils, taste, then spread them across a platter and arrange the carrots on top.
Chopped parsley and toasted pumpkin seeds add freshness and crunch. Serve with bread for two generous meals or as part of a larger table. The carrots can be warm rather than scorching; the important thing is to dress the lentils while they still absorb flavor readily.