Combine provolone, ricotta, parmesan, and garlic. Season with salt and pepper.
Steam spinach until wilted, about 1–2 minutes.
Press spinach with paper towels to remove moisture.
Spread 1 tsp butter on both sides of each bread slice.
On two slices, add spinach, basil, and cheese mixture.
Sprinkle sun-dried tomatoes, add remaining bread, and press gently.
Grill over medium-low heat for 4–6 minutes covered, then 2–3 minutes uncovered.
Slice and enjoy hot.
