Heat a large 11 or 12-inch skillet over medium heat. Add olive oil. Then add the onion and sauté for 5 minutes. Add the minced garlic. Sauté the garlic for 2 -3 minutes, until starting to brown.
Add the kidney beans and sauté over medium high for about 3 minutes, until they are coated with oil and heated through.
Add the spinach, and sauté over medium heat, stirring the spinach until wilted; let cook, stirring once, for 4 minutes. Season with salt and pepper.
Add the parmesan cheese, stir to combine, remove from heat, and keep warm until ready to serve.