The Baltimore lake trout sandwich is defined by a name that lies. There is no trout in it and nothing from a lake: the fish is whiting, a soft, cheap, mild ocean fish, dredged and fried hot. The build is the most stripped a fried-fish sandwich gets. Two slices of plain white bread, a fried fillet that overhangs them on every side, hot sauce, and that is the sandwich. The bread is not a structural roll engineered for the load; it is soft sliced bread chosen precisely because it gives way completely to the fish, and the imbalance is the entire identity.
The craft is in the fry and the deliberate fragility. Whiting is a delicate fish that cooks fast, so it is dredged in seasoned cornmeal or flour and fried hot and quick to set a crisp, sandy crust before the soft flesh overcooks. It comes out in pieces far larger than the bread, and that is intended: the white bread is there to give the hands a grip and to soak the oil and the hot sauce, not to contain the fish. There is no cooling sauce insulating the crust and no sturdy bun fighting the fillet, so the sandwich has to be eaten immediately, while the crust is still crisp and the bread has not yet surrendered. Saltines often come alongside as the only crunch the plate otherwise lacks, and hot sauce is applied straight onto the fish as the single seasoning that carries it.
The variations are small because the form is already at its minimum. The fish can shift to other cheap mild whitefish depending on what the corner carrier has; the heat ranges from a dash of vinegar pepper sauce to a heavy soak; some builds add a slice of white bread between two fillets rather than fillet between two slices. It belongs to the broader American fried-fish family, where sturdier rolls and bound sauces do structural work this sandwich refuses, and those codified builds each deserve their own article rather than being crowded in here.