In our house, lasagne is a cult dish - my men are huge fans. But I have to admit that I don't make it very often: between the béchamel sauce, the cooking of the sauces and the assembly, it's a time-consuming dish. So here's my express 'One Pot' version, which retains the comforting taste of lasagne while drastically reducing the time spent in the kitchen. Ready in 30 minutes, including cooking, it can be prepared directly in an ovenproof pan. Perfect for a weekday dinner, especially accompanied by my favourite green salad. Tip: if you want a browner gratin, finish off with 2 minutes under the broiler.