Grilled cheese from a restaurant, even though seemingly made with the same ingredients as you use at home, is a much more decadent experience. The cheese seems creamier and the bread seems butterier and crispier. To duplicate these results at home, you just need to stop thinking like a home cook and start thinking like you're deep in the throes of a busy restaurant kitchen.
The Case for Crust
Bread is the foundation of any grilled cheese sandwich. If you're going to the trouble of crafting a high-quality grilled cheese, you owe it to yourself to steer clear of thin, spongy, store-bought sandwich slices. Instead, opt for thickly sliced Texas toast or thick, hearty slices of sourdough. You can technically use any type of bread you want, but the key is that it should be thick. Thin bread absorbs some of the moisture from the cheese and some of the cooking oil, so it's moist on both sides. Sandwiches made with this type of bread seem flat, deflated and somewhat soggy.
If you're a purist, you want to use nothing but a classic, quality, thick-sliced, easy-melting American cheese. In some restaurants, you can get bacon, a fried egg, pickles, tomatoes and other toppings added to your grilled cheese. Make sure they're fairly dry. A soggy sandwich won't crisp up. If you're in the mood for something more on the gourmet side, or if you just happen to have some fancier cheeses on hand, you can always try them. Cheddar, Gouda, Swiss and provolone are good melty cheeses.
Flat is Where It's At
The main element that distinguishes the pros from the amateurs is the surface on which you cook your grilled cheese. Most people use skillets when making grilled cheese at home. Skillets, with their curved sides, can hold in moisture and heat unevenly. Restaurants use wide, well-seasoned flat tops. Restaurant cooks also take a "low and slow" approach to cooking. The medium-low heat over a long period of time creates that golden, crispy crust.
Cook It Like a Pro
Once you've picked out your bread and cheese and located a flat top, you're ready to put everything together. Brush the outsides of two pieces of bread with melted butter. Don't spread on globs of soft butter with a knife. Melted makes the bread crispier. Lay both pieces on the flat top butter-side down. Place an equal amount of cheese on both sides. Add your toppings. Let the two sides cook on medium-low heat for several minutes until the cheese has melted and the outsides are crisp and brown. Flip one side onto the other side, and serve.