This is a recipe I always turn to when I have a crowd to feed. It’s hugely popular with everyone, kids adore it, and the beauty of it is that it can all be made in advance before anyone arrives, so you’re free to enjoy yourself once they’re there. All you need to do is remember to turn the oven on!
2red onions, roughly diced
3red peppers, deseeded and roughly diced
280gbaby plum or cherry tomatoes, chopped
2tbspvegetable oil plus extra for coating
salt and black pepper
1 large courgette, cut into bite-sized pieces
a good bunch of basil, leaves roughly torn, plus extra to top
450mlcold whole milk
apinch of English mustard powder
100gmature Cheddar cheese, grated
60gvegetarian Parmesan-style cheese, grated
200gdried lasagne sheets
Heat the oven to 200°C/fan 180°C/gas mark 6.
In a large roasting tray, toss the aubergine, red onions, red peppers and tomatoes with the 2tablespoons of vegetable oil, and season with salt and black pepper. Cut the top off the garlic bulb in order to expose each clove at the top, then wrap it in foil and add it to the roasting tray.
Roast the vegetables in the oven for 35 minutes, then add the courgette and stir through the tomato purée. Return to the oven for 25 minutes, then remove from the oven and stir in the torn basil leaves.
When cool enough to handle, remove the garlic from the foil and squeeze the now-soft garlic flesh out of it, then stir it into the other vegetables.
While the vegetables are roasting, make the cheese sauce. Combine the milk, butter, flour and mustard powder in a saucepan, set it over a medium heat and whisk frequently until the butter has melted and the flour is all incorporated. Bring the mixture to the boil and cook, whisking regularly, until the sauce has thickened enough to coat the back of a spoon.
Remove the sauce from the heat, then whisk in the grated Cheddar and half the grated vegetarian Parmesan-style cheese. Taste, then season with salt and black pepper.
Bring a large pan of salted water to the boil, then cook the lasagne sheets in it for 8–10 minutes, until just al dente. Use tongs to remove them, then coat them in vegetable oil to prevent them from sticking to one another.
Assemble the lasagne in a large, rectangular ovenproof dish (about 30 × 20cm/12 × 8in and 10cm/4in deep). Put a layer of roasted vegetables in the base, top it with a layer of lasagne sheets, then a layer of cheese sauce, and repeat until you have used everything up. You should end with the cheese sauce on the top. Scatter the remaining Parmesan-style cheese over the top and return to the oven for 35–40 minutes, until browned and piping hot. Top with extra basil if desired.