Spinach Ruben Sandwich
1/8 Cup reduced-fat mayonnaise
2 teaspoons ketchup
2 teaspoons chopped capers
1 teaspoon chopped pickle or relish
3 teaspoons extra-virgin olive oil, divided
1 small red onion, thinly sliced or 3 shallots finely diced
1 cup sliced mushrooms
1 bunch spinach, cleaned and stemmed
Freshly ground pepper to taste
Pinch of nutmeg, freshly ground
4 slices rye bread
4 thin slices Swiss cheese
1/2 cup sauerkraut
1. To prepare Russian dressing: Whisk mayonnaise and ketchup in a small bowl until smooth. Stir in capers and pickle (or relish).
2. To prepare sandwiches: Heat 2 teaspoons oil in a large nonstick skillet over medium-high heat. Add onion or shallots and mushrooms; cook, stirring often, until the onion is softened, 4 minutes. Add spinach and cook, stirring, until it has wilted, 1 to 2 minutes. Add salt, pepper and nutmeg to taste. Transfer the mixture to a plate.
3. Coat the pan with the remaining 1 teaspoon oil and return to medium heat. Add the bread; divide cheese equally among the slices. Divide sauerkraut between 2 slices and divide the spinach mixture between the other 2 slices; cook until the cheese has melted and the bread is golden brown, 4 to 6 minutes. Transfer sandwich halves to a cutting board. Divide the dressing between the spinach halves. Carefully place the sauerkraut halves on top. Cut sandwiches in half and serve.