Wash and dry all produce. Adjust rack to middle position and preheat oven to 400 degrees. Line a baking sheet with aluminum foil and sprinkle with a drizzle of olive oil. Halve and peel onion; finely chop one half (save the other for another use). Mince garlic.

In a medium bowl, mix together pork, panko, 1/4 cup onion, half the garlic, half the Tuscan heat spice, and a few large pinches of salt and pepper. Divide into 16 pieces and shape each into a meatball. Place on foil-lined baking sheet. Bake in oven until cooked through, 18-20 minutes.

Meanwhile, heat a drizzle of olive oil in a small pan over medium heat. Add remaining onion and cook until starting to soften, 3 minutes. Toss in remaining garlic and Tuscan heat spice and cook until fragrant, 1 minute more.

Stir tomatoes, 1 tsp sugar, and a large pinch of salt and pepper into pan. Bring to a simmer and let bubble until thickened, 3-4 minutes. Meanwhile, zest 1 tsp zest from lemon, then halve and squeeze 1 TBSP juice into a small bowl. Halve zucchini lengthwise, then slice crosswise into 1/4-inch-thick half-moons. Remove pan from heat once sauce thickens and stir in 1 TBSP butter.

Heat a large drizzle of olive oil in a medium pan over medium-high heat. Add zucchini and a pinch of salt and pepper. Cook, tossing, until softened, about 5 minutes. Toss in reserved lemon juice and zest. Set aside off heat. Remove meatballs from sheet once baked and heat broiler to high. Cut meatballs in half. Split ciabattas in half and sprinkle cut sides with a drizzle of olive oil each. Arrange bottom halves cut side up on same baking sheet.

Spread a little sauce on each ciabatta bottom. Arrange meatballs on top (serve any extras on the side if they don’t all fit). Spoon over remaining sauce and sprinkle with mozzarella. Top with remaining ciabatta halves and place under broiler. Broil until mozzarella melts, 2-3 minutes. Divide between plates and serve with zucchini.