Creamy Mushroom Green Bean Casserole

Green bean casserole has a funny history for a dish that shows up on so many tables. It was built in the 1950s by a test kitchen working for a soup company, who wanted an easy way to use a can of condensed soup and a bag of crispy onions. Nobody in that kitchen was thinking about lightening it up. This version keeps the spirit of the original, a creamy sauce under a crunchy top, but swaps in a few things that make it feel a little less heavy on the spoon.

The real star here is the mushrooms. White button mushrooms are simply the same fungus as cremini and portobello, picked at different stages of growth. Sliced and cooked down in a pan with a bit of oil and margarine, they release their liquid and then turn deep and savory. That savory depth is why the sauce tastes so satisfying even with light Swiss and 1% milk. Give the mushrooms the full four or five minutes. Pale, rushed mushrooms make a flat sauce, and patient ones make the whole dish taste like it took more effort than it did.

A couple of small things to watch. Cornstarch needs to be whisked with cold water before it goes into the hot pan, or it clumps and you get lumps you cannot stir out. And once the sauce has thickened, take it off the heat before you fold in the green beans, so they stay tender-crisp instead of turning soft and grey in the oven. Drain the canned beans well. A little extra water in the dish will thin the sauce and make the corn flake topping soggy.

Leftovers keep well in the fridge for about three days in a covered container. The topping will soften, so if you want it crunchy again, scatter a few fresh crushed corn flakes over the reheated portion and warm it in a 350 degree oven, or briefly under the broiler while watching closely. The sauce also makes a nice base for a quick weeknight plate: spoon it over baked potato or stir a spoonful into a bowl of brown rice with some leftover chicken.

For a fuller meal, this pairs well with something simple and bright. A crisp salad with a sharp vinaigrette cuts through the richness, and a plate of roasted chicken or a grilled fish fillet balances the creamy side without much fuss. If you are building a spread for a crowd, these recipes sit nicely alongside it:

• Cannellini Bean Burgers with Mango Slaw for a meatless main with a crunchy, tangy side.
• Savory Chicken and Vegetable Pot Pie if you want something comforting that also feels like a full dinner.
• Tuna Pasta Bake with Spinach and Mushrooms for another creamy bake that works on the same table.