1.

Heat the oven to 220°C (200°C fan) and line two large baking trays with baking paper.

2.

Slice the courgettes lengthways into strips about 5mm thick. Lay them on the trays, brush lightly with the oil, and roast until softened (10–12 minutes). This removes excess water so the lasagne isn't soggy. Reduce the oven to 200°C (180°C fan).

3.

Meanwhile, heat a large frying pan over a medium-high heat. Add the mince without oil, and cook, breaking it up, until browned (6–8 minutes). Spoon off any fat.

4.

Add the onion and cook until soft (5 minutes). Add the garlic and cook until fragrant (1 minute).

5.

Stir in the tomatoes, lentils, crumbled stock cube, Worcestershire sauce, herbs and pepper. Simmer uncovered until thick (10–15 minutes). A thick sauce stops the lasagne from being watery.

6.

Spread a third of the sauce over the base of the ovenproof dish and top with a layer of courgette. Repeat, finishing with a layer of sauce.

7.

Scatter over the mozzarella and Parmesan.

8.

Bake until bubbling and golden (25–30 minutes). Rest for 10 minutes before cutting, so it holds its shape.

9.

To make ahead: Assemble it up to 24 hours ahead, then cover and refrigerate. Add 10 minutes to the baking time.