Put the tuna, cottage cheese, mayonnaise, red onion and chives in a bowl and stir well. Season to taste with freshly squeezed lemon juice, salt and freshly ground pepper.
Warm the rolls in a toaster or a panini press.
Divide the tuna salad between the bottom halves of the rolls and scatter over microgreens or a little crisp lettuce. Spread the top halves with chilli mayo and close the sandwiches.
Serve straight away, or wrap them up for a packed lunch, a picnic or the like.