If you're looking for an escarole substitute, you could try frisee lettuce. Escarole lettuce is often used in soups, especially Italian ones like minestrone, but it can be hard to find depending on where you live. There are a few different options when looking for an escarole substitute that will work well as an ingredient in soup. First of all, there's frisee lettuce. This is also a type of endive and is slightly more bitter than escarole, but it's probably the closest thing to it in terms of taste and texture that you'll be able to find. If you want to use frisee lettuce as an escarole substitute, use about the same amount of frisee as the recipe calls for escarole. You can also try Kale. They are great for soups as well.