Heat your oven to 200°C /Fan 190°C /Gas 6.
Slice the tops off the carrots and set aside. Scrub the carrots. Halve lengthways and lay in a roasting tin. Toss with 1 tbsp oil and a little salt and pepper. Roast for 25 mins, turning occasionally, till a little charred.
Make the dressing: mash together 15g of the feta, 1 tsp oil and the juice of the lemon. Stir 1 tbsp boiling water into the dressing to loosen it up a little. Have a taste and add salt and pepper if needed.
Halve the plums, and use a spoon to scoop the stones out. Slice into wedges.
Drain the lentils and rinse well. Tip into a bowl. Thinly slice half the mint leaves and add to the bowl. Finely chop a handful of the carrot tops and add them too. Stir in half the dressing.
Spoon the lentils onto each plate or a serving platter. Pile the roast carrots and plum wedges on top, and scatter some of the rocket leaves. Crumble over the remaining feta. Finish with more of the dressing and the remaining mint.