In a mixing bowl, mash the tuna with a fork until well shredded. Combine it with the mayo, lime juice and salt to taste.
Pre-heat the broiler, or you can use toaster oven.
Divide the tuna mixture between four slices of bread. Divide the poblano strips on top of the tuna, and top with the cheese. Place under broiler, or in the toaster oven, until the cheese is melted.
Place the remaining slices of toasted bread on top to close the sandwiches and serve.