Our kitchen is being remodeled and so I've been eating lots of sandwiches the last few weeks. I've discovered a combination that I find incredible.
Start with potato bread. It has large slices and is very moist. Spread a layer of butter on each piece of bread and then a layer of Best Foods mayonnaise on top of the butter layer.
Get the sweetest onion you can find, a Vidalia or similar, preferably one without a lot of bite. Cut it into thin slices, enough for two full layers on the sandwich. Salt and pepper each layer. Put one layer on one of the slice of bread.
Cook four Anaheim chiles on the grill until they are blistered and then put them into a plastic bag. The hot moisture inside the bag will make it easier to peel off the blistered outer layer.
Then open up a chile and clean out most of the seeds and spread it on one piece of bread over a layer of onions. Add salt and pepper. Then while the chile is still hot, add a large slice of cheese - I used Tillamook Colby Jack. Then add another peeled and opened chile on top of the cheese, salt and pepper. Then add another layer of cheese, a layer of chile, salt and pepper, a layer of onion and the final layer of chile, salt and pepper, followed by the other piece of bread.
The combination of salty, buttery mayo mixes in with the sweet and crunchy onion, the melting cheese and the denser, more bitter chile, for a wonderful flavor and texture combination. Thinner onions are better than thicker onions and four Anaheim chiles are better than three.