Boil tripe with carrots, onion, leek, celery, and bouquet garni in water for 3-4 hours until soft.
Drain the tripe, discard vegetables, and cut the meat into six rectangular pieces.
Whisk eggs with sunflower oil in a bowl and process crackers into fine crumbs in another bowl.
Dip tripe pieces into the egg mixture then the cracker crumbs and place on a lined tray.
Melt butter in a pan and fry tripe with spring onions for 3 minutes per side until brown.
Mix cornichons, shallot, capers, mayonnaise, and lemon juice in a small bowl to make sauce gribiche.
Serve the hot crumbed tripe with steamed potatoes and the prepared sauce.