I grew witloof chicory once and it was too bitter for me. The same is true with radicchio and endive, that I have had in restaurants. He suggested cooking escarole. Wonderful! It's very early and stays around longer in summer heat, certainly longer than spinach. I learned to like lettuce outside of a sandwich by having it sauteed with bacon. Escarole reminds me of that "wilted lettuce" an elderly lady prepared for me back in the '60's.
Orach volunteers for me in my garden. Now, I like that spinach relative raw in salads

Steve