Preheat a cast-iron skillet over low heat.
Spread a teaspoon of mayonnaise on two slices of sourdough bread.
This is the secret to help brown the bread evenly!
Use freshly grated cheese for even melting and the best flavor.
I like to use a combination of cheddar and gruyère for a sharp flavor and ooey, gooey-ness.
Place the other bread slice mayo-side up on top and put a lid on top of the bread.
Cook over low heat for 2-3 minutes until the bottoms browns, flip, and repeat.
To get a great grilled cheese pull, you can add a slice of mozzarella cheese at the very end of baking.
This will create that photogenic, stringy cheese pull!
Use a mix of cheeses or add other toppings to your grilled cheese.
Other favorites include brie and fig jam, bacon and tomato, miso butter and garlic, kimchi, etc.