Preheat oven to 450 degrees. Wash and dry all produce. Halve, peel, and thinly slice onion. Peel and finely chop carrot. Finely chop celery. Zest and quarter lemon (quarter both lemons for 4 servings) Halve, core, and dice half the apple into 1/2-inch pieces (dice whole apple for 4). Rinse and pat shrimp dry with paper towels.

In a medium bowl, toss diced apple with juice from 1 lemon wedge and 1/4 tsp sugar (2 lemon wedges and 1/2 tsp sugar for 4 servings). Roughly chop parsley. Mince garlic. Heat a large drizzle of olive oil in a large pan over medium heat. Add onion, carrot, and celery; season with salt and pepper. Cook until softened, 4-5 minutes.

Add half the garlic, 2 tsp Italian Seasoning (4 tsp for 4 servings), and a pinch of chili flakes to pan with veggies. Cook until fragrant, 30 seconds to 1 minute. Add stock concentrate, tomatoes, 11/2 cups water, and juice from 2 lemon wedges (3 cups water and 4 lemon wedges for 4); season with salt (we used 1 tsp) and pepper. Bring to a boil, then reduce heat to medium. Simmer until slightly reduced, 8-10 minutes.

Meanwhile, place remaining garlic and 2 TBSP butter (4 TBSP for 4 servings) in a small, microwave-safe bowl. Microwave until just softened, 10-15 seconds. Season with salt and a pinch of chili flakes, if desired. Halve ciabatta; spread cut sides with garlic butter.

Lightly oil a baking sheet. Sprinkle Parmesan into two 3-inch-wide circles (four circles for 4) onto prepared sheet. Bake on top rack until cheese is melted and crispy at the edges, 5-7 minutes. Let frico cool for 1 minute on sheet, then transfer to a paper-towel-lined plate. Once cool enough to handle, break into bite-sized pieces. Place ciabatta, cut sides up, on the same baking sheet. Bake on same rack until golden brown, 5-7 minutes. Halve on a diagonal.

Add shrimp, half the parsley, and as much lemon zest as you like to broth. Simmer until shrimp is cooked through, 3-4 minutes. Season with salt and pepper. To bowl with pickled apple, add mixed greens, frico, a drizzle of olive oil, salt, and pepper; toss to coat. Divide cioppino between bowls. Garnish with remaining parsley and chili flakes to taste. Serve with salad, garlic bread, and remaining lemon wedges on the side.