This recipe is original, like all you will see on this blog, and absolutely one of my favorites. Imagine French onion soup, with an exaggerated crouton and an ultimately minimalist stock.
French Onion Sandwich
3 lb yellow onion
4 T unsalted butter
2 pinches sugar
1/2 t kosher salt
1 sprig fresh thyme (leaves only)
1/4 C white wine
3/4 C shredded gruyere cheese (Swiss is a good substitute)
1 ciabatta loaf or baguette
Slice onions crosswise (not pole to pole) into 1/8" strips. Melt butter over medium heat. Add onions, salt and sugar. Cover and cook for 10 min. Reduce heat to medium low. Cook onions until deeply caramelized--60 to 90 minutes. (Admittedly, this is a long time. It's definitely "slow food.") Add thyme and wine. Stirl until absorbed. Remove from heat.
Slice bread into 3 sandwich size pieces splitting each into a top and bottom. Butter each slice liberally and place open faced on baking sheet. Divide onions evenly between the three bottom pieces. Divide cheese evenly among three tops. Bake at 425 until cheese is melted and lightly browned in spots.
Assemble tops and bottoms and serve.
Makes 3 sandwiches. My apologies for the unusual serving size -- increase or decrease proportions as needed for your table, without adjustments.