A nice fresh pea soup can be great sometimes, and also a good thing to do with leftovers. This worked well for me when I had some leftover spring onions, creme fraiche and wasabi. You can of course leave out the wasabi, or swap the creme fraiche for cream or a dab of milk, or you could add watercress perhaps.
Boil a kettle.
In a smallish pan melt the butter. Chop the spring onions, and fry the white bits gently to soften them, about 4 minutes. Then add the green bits of the spring onions, as well as the peas and the tiny dab of wasabi.
Turn up the heat and also add the boiling water, just enough to cover things. Once you've brought the pan to the boil you can turn it right down low, put a lid on it, and let it bubble gently for approx 10 minutes, no need for more.
Take the pan off the heat, and with a hand blender you can whizz up the pan's contents to blend it to a smooth soup. Add the black pepper and creme fraiche and stir it through.