Here is an easy soup to make with your new or leftover veggies. In my case my soup pot is filled with a roughly chopped entire head or stalk of celery. (One piece of celery is a rib. A stalk is a bunch like you buy at the store.) Reserve the leaves for garnish. Then a roughly chopped largish potato or several small ones are added. I have Yukon golds and I do not even peel them. I also stick in a chopped onion and whole garlic cloves (2 or 3). Salt. Use a glug of olive oil to get things sizzling. When the onion wilts add 3 cups of vegetable or chicken stock or enough to cover. Simmer until everything is soft. Whiz it up in a blender when it has cooled down a bit. Correct the seasoning.
You can add some cream to finish or just leave it the way it is and drizzle a little olive oil over the top and garnish with the celery leaves. You can actually do this with pretty much any vegetables you have.