Decide whether your recipe needs raw crunch (salad/cups) or cooked leaf tenderness (braise/sauté).
For cooked dishes, choose escarole or radicchio; for extra-bitter flavor control, rinse radicchio leaves well.
For raw substitutes, pick romaine hearts (mild) or iceberg (very mild); to imitate endive’s bite, add a small acidic boost.
Trim tough centers, then prep by matching bite size to your endive leaves (quarters for cups, shred for salads).
Taste after seasoning: increase salt or acid in small steps if your substitute is milder than endive.