If you love Grilled Cheese with Tomato, you've got to try this elevated version with pesto and olive tapenade. Swap out your standard sandwich bread for a hearty sourdough, trade the American cheese for Italian fontina and fresh mozzarella, and you've got yourself an exceptional sandwich!
In a small bowl, stir together the butter and garlic powder until combined.
Spread the garlic butter on one side of each bread slice, dividing it evenly. Place both slices, buttered-side down, on a clean cutting board. Spread the tapenade on one slice and the pesto on the other. Layer the fontina, tomato slices, and mozzarella on top of the tapenade. Finish with the pesto bread, buttered-side up.
Heat a medium nonstick skillet over medium-low heat. Using a wide spatula, place the sandwich in the pan, cover, and cook until the bottom is nicely browned, about 6 to 8 minutes. Turn and cook until the second side is browned and the cheese is melted, about 4 to 6 minutes longer.
Cut the sandwich in half, if desired, and serve immediately.
Notes
To flip this sandwich I recommend removing it from the skillet with a large spatula and placing on a plate. Then place an inverted plate on top, flip the whole thing over, then use the spatula to move the flipped sandwich from the plate back to the hot skillet. This will yield the least messy results and none of the filling should fall out.
Italian Fontina Val d’Aosta may be harder to find, as most American grocery stores will sell another variety (domestic or often from Swedish or Denmark), but I have found the Italian cheese at Whole Foods and at dedicated cheese shops. In a pinch, you can use other types of Fontina, but it's worth the extra effort to find Fontina Val d’Aosta if you can.
Note that this cheese is typically made with animal rennet which means it isn't vegetarian. If you're vegetarian, use a vegetarian cheese instead such as Boar's Head brand vegetarian Fontina.