This morning I made them for a quick breakfast in our toaster oven. When I am making for a crowd, I use a large cookie sheet in the regular oven.
My daughter, who is a vegetarian, eats the croissant and cheese or adds a scrambled egg.
I start with Croissants from the bakery. The ones I used today are cocktail size but if I am making lunch, I buy the full-size. You can use any ham you want. I like Sara Lee Honey Ham but I have also used left-over spiral ham from home or ham from the deli. The custom slices cheese work great for the smaller croissants. One slice broken in half and then one half broken again covers the entire croissant. I use three to four slices of ham. If using honey mustard, smear on to the croissant top and close. If using strawberry jam, I add that after it is warm.
I bake in a 400 degrees, pre-heated oven for 10 minutes or until the cheese is melted and the croissant is golden brown. The croissant will be a little crisp on top but still soft on the inside.