Lately I've been buying the big costco bag of spinach to make green smoothies. However, I somehow don't manage to make them as often as I want to and so I usually end up with extra spinach that goes bad. Sooo, when I have a recipe calling for frozen spinach, I often just chop up some regular spinach and toss it in the pot. I either just fill the pan and chop with scissors or fill a cup like this and chop. Just be advised that by weight that small little box is a lot more fresh spinach than you think. See the white colander in the picture? I used that to weigh the amount of spinach I needed and I probably filled the colander. Don't worry, cooked it wilts and turns out just fine.