Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 450 degrees. Wash and dry produce.

Cut potatoes into ½-inch-thick wedges. Toss on one half of a baking sheet with a large drizzle of oil, half the Italian Seasoning (you’ll use the rest later), salt, and pepper. (For 4, spread potatoes out across entire sheet.)

Roast on top rack until lightly browned and tender, 10 minutes (you’ll add more to the sheet then). 

Peel and slice onion into ½-inch-thick rounds. Halve, core, and thinly slice bell pepper into strips. Trim and slice zucchini crosswise into ¼-inch-thick rounds.

In a medium bowl, toss onion and bell pepper with a drizzle of olive oil, salt, and pepper.

Once potatoes have roasted 10 minutes, remove sheet from oven. Carefully toss onion and bell pepper on empty side. (For 4 servings, leave potatoes roasting; add veggies to a second sheet and roast on middle rack.)

Return to top rack until potatoes are browned and veggies are tender, 10-15 minutes more.

Toss zucchini in bowl used for veggies with a drizzle of oil, salt, and pepper.

Heat a drizzle of oil in a large pan over medium-high heat. Add zucchini in a single layer; cook until golden brown and slightly tender, 2-4 minutes per side.

Turn off heat; transfer to a plate. Wipe out pan.

Meanwhile, in a small bowl, combine mayonnaise, half the garlic powder (we sent more—use the rest as you like), remaining Italian Seasoning, and a drizzle of olive oil (large drizzle for 4 servings). Season with salt and pepper to taste.

Spread half the sourdough slices with a thin layer of aioli. Spread remaining sourdough slices with smoky red pepper crema.

Fill with even layers of mozzarella, bell pepper, onion, and zucchini (we used 4-6 zucchini slices per sandwich; you may have some left over). Close sandwiches.

Heat a drizzle of oil in pan used for zucchini over medium heat. Once hot, add sandwiches; press down with a spatula or heavy-bottomed pan. Cook, pressing occasionally, until bread is toasted and cheese melts, 2-4 minutes per side. (For 4 servings, work in batches or use a second pan, adding more oil as necessary.) TIP: Lower heat if sandwiches begin to brown too quickly!

Halve panini on a diagonal and divide between plates. Serve with potato wedges and remaining aioli on the side for dipping. TIP: Serve any remaining zucchini slices on the side!