That’s what a Croque Monsieur can and should be, sofa king good. When I look back on current circumstances, I will include the good with the bad. For us, the weekly sandwich has been ooh la la. This week off to France for an always better than ham and cheese.
I adjusted the Bon Appetit recipe below, starting my bottom layer of bread in a butter greased skillet to crisp it up. I subbed a teaspoon of Dijon for the whole grain mustard. It could’ve used a touch more. Use any ham and Swiss that you have, but the gruyere in the topping makes a big difference, or at least a nutty Parmesan if desperate. I did not have or care about herbes de Provence. At the end I threw the broiler on for about a minute.
I Am Not A Restaurant! 
Looks great . I remember your MArtha Sirius show . Loved it !
Do you recall Use it Wednesday ? Who was that host ? I think of her a lot these past few weeks!
Keep posting !