How to Make It
In a medium bowl, mix the mayonnaise with the 1 tablespoon of olive oil from the tuna, the lemon juice, Dijon mustard, celery, roasted garlic, parsley, capers and celery seeds. Mix in the tuna and season with salt and pepper.
Spoon the tuna salad onto 4 slices of multigrain bread, top each one with 1 ounce of Gruyère and another slice of bread. Toast the sandwiches in a panini press until they’re golden and the cheese is melted.