Use the late summer surplus of vegetables to make these paninis - pressed grilled cheese sandwiches. Smarts: We like bell peppers and zucchini in these sandwiches, but just about any summer vegetable will work.
Heat a large grill pan or skillet with some oil over medium-high heat. Add bell peppers and zucchini slices to heated oil. Cook vegetables on both sides until very tender, 5 to 7 minutes total. Season with some salt as they cook.
While vegetables cook, spread butter on one side of all the slices of bread. Lay out half the bread buttered-side down. Top with mustard and mayonnaise, cheese, bell peppers, zucchini and remaining bread buttered-side up. Continue until all sandwiches are assembled.
Return grill pan or skillet to stovetop over medium heat. Place sandwiches onto heated surface (as many as can fit) and press down throughout the grilling process with a spatula. (You can also place a heavy skillet or Dutch oven on top to press the sandwiches down like with a panini press!) Flip sandwiches once the first side is golden, ~ 3 to 4 minutes and continue cooking until cheese is melted.
Slice paninis in half and serve with pineapple spears on the side. Enjoy!