01 -
In a bowl, toss together the tuna you've drained, diced celery, red peppers, scallion, yogurt, Dijon mustard, and some pepper. Stir until everything's combined nicely.
02 -
Take 1 teaspoon of mayo (or spreadable butter) and coat one side of each bread slice. Lay 2 slices down, mayo-side facing down. Spread half the tuna mix on each one, add a slice of cheddar over the tuna, and top with the other bread slices, mayo-side up.
03 -
Warm up a big pan over medium heat. Place your sandwiches in the pan and let them cook until golden on one side, about 3-5 minutes. Flip, then cook the other side for another 3-5 minutes until the cheese melts and the bread crisps up.
04 -
Take the sandwiches out of the pan and serve right away while they're hot and gooey.