Finely dice 1 stalk of celery and thinly slice 1 apple. Cut remaining celery into sticks and remaining apples into wedges.

Drain tuna and mix in a bowl with mayonnaise, celery, and mustard.

Toast bread and top 4 slices with tuna. Add spinach, along with a few slices of apple, then top each with a second slice of bread. Cut sandwiches in half or quarters.

Serve with celery sticks, apples wedges, and almonds.