2. **Assemble the sandwiches**:
Butter one side of each slice of bread. Place two slices, butter-side down, in a skillet. Top with cheese slices and a spoonful of caramelized onions. Cover with remaining bread, butter-side up.
3. **Grill until golden**:
Cook over medium heat for 3–4 minutes per side, pressing lightly with a spatula, until the bread is golden and crispy and the cheese is fully melted.
4. **Serve hot**, with a side of tomato soup, pickles, or just on its own—Hollywood-style.
—
## 💡 Pro Tips
* Try mixing cheeses—**cheddar and mozzarella** or **Gouda and Swiss** add great flavor.
* Add a touch of **mustard or aioli** inside the sandwich for extra depth.
* Want some crunch? Add **thin apple slices** for a sweet-savory balance.
—
## 🎬 Final Thoughts
