To make the white sauce, place the butter and plain flour in a bowl and microwave for 2 minutes and 30 seconds.

Take the bowl out of the microwave and stir well.

Add the milk gradually and stir well.

Cover the bowl with cling wrap and microwave for 3 minutes.

Take the bowl out of the microwave and remove the cling wrap and stir well.

Put the cling wrap back on the bowl and microwave for a further 2 minutes.

Take it out of the microwave and stir well.

To make the potage, slice the onion thinly and defrost the soybeans.

Heat 1tbs butter in a frying pan over medium heat.

Add the onion and soybeans to cook.

In a large bowl pour the milk, cream, and white sauce and mix them well.

Add the cooked onion and edamame soybeans and beat them with a hand held electric mixer.

Strain the soup into a large sauce pan and bring to simmer.

Add salt and pepper to taste and drizzle a little bit of cream to serve.