Roasted Tomato Slices with Spinach and Cheese

Marinate sliced tomatoes in balsamic vinegar for 5-6 hours.
Bake at 350 until tender (usually 7-8 minutes).
Sauté spinach with garlic and a pinch of Himalayan salt.
Add spinach mixture on top of tomatoes.
Sprinkle with chopped basil and your favorite cheese.
Broil until cheese is golden brown