Preheat the oven to 200°C / Fan 190°C / Gas 6.
Top and tail and peel the carrots, saving some of the green tops. Halve lengthways and scatter onto an oven dish. Toss with 1 tbsp of oil and a little seasoning, then roast in the hot oven for 25 mins, turning occasionally.
Make the dressing. Combine 1 tbsp of the cheese, 1 tsp of oil and the juice of the lemon. Fill up the kettle and turn on. Stir 1 tbsp of boiling water into the dressing to loosen it up a little. Have a taste and add seasoning if needed.
Halve the plums, and use a spoon to scoop the stones out.
Drain the lentils and rinse well. Tip into a bowl. Thinly slice half of the mint and add to the bowl along with any reserved carrot tops and half of the dressing. Stir to combine.
Spoon the lentils onto each plate or a serving platter. Pile the roasted carrots and plums on top, and scatter some of the rocket leaves. Finish with more of the dressing and the remaining mint.