Chokos have appeared in greengrocers’ shops only in recent years – as one of the easiest and most prolific vegetables to grow, they used to be such a popular ‘back fence’ crop that everyone knew someone wanting to give away their surplus.
Cut the chokos in quarters and peel and core them under cold running water. Cook the chokos in a saucepan of boiling salted water for 5–8 minutes, or until just tender when tested with a skewer. Drain and place the chokos in a serving dish.
Meanwhile, to make the white sauce, melt the butter in a small saucepan until hot and bubbling. Add the flour and stir constantly for 1 minute. Remove from the heat and add the milk in a slow, steady stream, whisking constantly to avoid the sauce becoming lumpy. Return the saucepan to the heat and cook, stirring constantly, on medium-high heat until the sauce comes to the boil and thickens. Season to taste with salt and black pepper. Pour the sauce over the cooked chokos and serve immediately.