The Assembly Mistake That's Making Your Fish Sandwich Fall Apart
Making a great fish sandwich is relatively easy, but that doesn't mean it's a totally foolproof process. Alas, if you decide to layer your fish on top of all of the other fixings, you may run into some issues when it's time to chow down.
The crux of the matter is simply gravity. The fish filet is the heaviest and most solid part of the sandwich, so layering it towards the bottom bun is the best way to ensure stability. Additions like lettuce also commonly sit at the bottom, which is also fine, just make sure to dry your greens off else the fish may slide off. Additionally, there are many dos and don'ts for breading a fish sandwich, and a big "don't" is letting your fried filet get all soggy due to lying on top of wet ingredients. Keep the other sandwich ingredients to a minimum on the bottom and rather layer them on top of the fish for the cleanest assembly.
McDonald's Filet-O-Fish famously features a slice of cheese at the bottom of the stack, and this sure seems to be a good strategy. Melted cheese may slightly soften the filet breading, but it will also act as a mild adhesive, preventing the fish from sliding off the bun.
To bread or not to bread
There are plenty of fish in the sea, but not all of them are good choices for your sandwich. If you're looking for a crispy fried filet, white fish is the way to go. Tilapia is thinner so it may not have as much meat, but it fries quickly and easily, and its milder taste lends itself well to experimenting with seasonings. For a heartier choice, cod and haddock are the go-tos for fried fish and chips, so they transfer onto sandwiches excellently. With these options, you don't need to overdo the seasonings as the fish themselves are pretty chunky, so they may take over those additional flavors in any case. For thicker fried white fish, keep the toppings simple and allow the filet to speak for itself.
If you want to forgo the breading, salmon and halibut are great for grilling or baking and their thickness ensures a filling meal. For a more unconventional route, catfish is a delicious sandwich filler and its flaky texture gives you a fish sandwich that falls apart in the way you'd actually want. Non-breaded filets allow more room for creativity in seasonings and offer a lighter meal. They also hold up better throughout the day whereas breading can get soggy.