Waffle Sandwich With Cheese, Spinach And Spicy Mustard - cooking recipe

Ingredients

1 roma (plum) tomato, thinly sliced
salt and ground black pepper to taste
2 teaspoons butter, softened
4 thickly-sliced pieces multigrain bread
1 teaspoon spicy brown mustard
1 cup fresh spinach, or to taste
4 slices part-skim mozzarella cheese
2 teaspoons chopped sweet onion

Preparation

Preheat a waffle iron according to manufacturer's instructions.
Arrange tomato slices on a work surface, pouring off any excess juice. Season tomato slices with salt and pepper.
Spread 1/2 teaspoon butter onto 1 side of each bread slice. Lay 1 bread slice, butter-side down, in the hot waffle iron. Spread 1/2 teaspoon mustard onto bread slice in waffle iron; top with 1/4 cup spinach, 2 slices mozzarella cheese, 1 teaspoon onion, half the tomato slices, and 1/4 cup spinach, respectively. Lay 1 slice bread, butter-side up, atop the spinach layer.
Close waffle iron and toast sandwich until lightly browned, about 2 minutes. Repeat with remaining ingredients.