Lay the ciabatta bread slices on a flat surface, spread one side with butter and turn over, butter-side down.
Top with prosciutto, basil and Dolcelatte, then place the other slice of bread on top, butter-side up.
Heat a non-stick frying pan, add the sandwich and pan fry for three minutes on each side. Transfer to a plate and cut into triangles.
For the salad, mix the Little Gem lettuce, olive oil and balsamic vinegar in a small bowl.
To serve, pile the Little Gem lettuce mixture onto a serving plate, top with the croque monsieur and serve immediately.