Melted cheese toasties are the ultimate lunch time treat!
Spread the mayo on each to each slice of bread (this is the key to a golden, crunchy toastie!) Heat a small skillet over a medium heat, add half of the butter until it melts. Place one slice of bread, mayo side down, top with the cheese, tomato slices, spinach and season with pepper. Top with the second slice of bread, mayo side up.
When the underside is golden brown (about 4 minutes) turn the sandwich and add the remaining butter. Press the sandwich down to brown and help melt the cheese but be gentle. Cook until golden brown. Serve with soup if you're feeling extra!