Finnish summer soup

Tonight we tried a recipe for Finnish Summer Soup from that website I like, and it was a resounding success. I substituted rather more homely ingredients -- ordinary brown potatoes, an ordinary white onion, black pepper, broccoli instead of cauliflower -- and we liked it very much. I also added some extra water, salt, and pepper, and halved the peas, on the grounds that two cups of peas were excessive. It made plenty of leftovers. Yummy!

To be sure, almost anything with half-and-half and butter would be good!