Growing up, my mother cooked dinner for our family most nights. On the rare occasions when my parents went out, we either ate pizza or got Chinese food. Because of this, chicken and broccoli has consistently been one of the most important relationships in my life. This sandwich harnesses that magic, tops it with a spicy apple giardiniera (an Italian relish of pickled vegetables, which you can make milder by using green bell pepper instead of jalapeño), and rounds it out with mayo and cilantro. But feel free to skip the sandwich and just eat these meatballs, an amazing snack straight out of the refrigerator.
To make the giardiniera, combine the water, vinegar, 1 tablespoon of the salt, 2 teaspoons of the maple syrup, the star anise, and the bay leaves in a small saucepan and bring to a boil over high heat. Meanwhile, thinly slice the fennel, apples, and jalapeño, and place into a nonreactive container. Pour the brine over the mixture and set aside to cool. Once cool, cover and refrigerate for at least 1 hour and up to 2 weeks.
Heat the oven to 400°F (200°C). Roughly chop the broccoli. On a rimmed sheet pan, toss together the broccoli, garlic, and oil. Roast for 15 minutes, or until the broccoli is caramelized but still crunchy.
Meanwhile, grind the chicken if not using preground. To grind it yourself, cut the boneless thigh meat into even 1-inch (2.5cm) pieces. Working in small batches, place it in your food processor and pulse to finely chop but avoid turning it into a mousse. Transfer the chicken to a mixing bowl.
Once the broccoli is caramelized, transfer it to the food processor and pulse to chop. Place it in the mixing bowl with the chicken and add the panko, egg, Parmesan, salt, and maple syrup. Mix well.
Grease the sheet pan with olive oil or cooking spray. Form 12 even meatballs, approximately 1 inch (2.5cm) in size, and spread them out on the tray. Bake for 12 to 15 minutes, flipping once halfway through, or until the meatballs are cooked through, firm to the touch, and not at all pink.
To assemble the subs, spread mayo on both sides of the hero rolls. Halve all of the meatballs and arrange them in the rolls. Top with a little giardiniera (avoiding the bay leaves) and a lot of cilantro, stems and all!