Preheat the oven to 400°F/180C and mince the garlic. Slice the eggplant lengthwise, about 1/4 inch thick. Brush or rub a little olive oil on each side of the eggplant slices and place on a baking sheet lined with parchment paper or a baking stone. Sprinkle it with salt and pepper.
Step 2
Place in the oven for 7-10 minutes, or until the eggplant is hot and starting to cook down. Meanwhile, to a skillet, add 1/2 tablespoon olive oil and sauté the garlic and onion until soft for about 3-4 minutes. Season with salt and pepper. Add pizza sauce and spinach to the skillet and cook for 1-2 additional minutes until the mixture is warm and the spinach has wilted.
Step 3
Remove the eggplant slices from the oven, and top each with the onion and spinach mixture. Sprinkle it with cheese and place in the oven for approximately 5 minutes, or until the cheese has melted.
Step 4
Serve immediately with more fresh basil and crushed red pepper. Store any leftovers in an airtight container and refrigerate them for up to three days. When ready to enjoy, reheat the slices in the oven or microwave until heated through and serve.