1 red onion, peeled, halved lengthwise, and thinly sliced
1/4 cup (a generous handful) flat-leaf parsley leaves, chopped
2 tablespoons red wine vinegar
Extra-virgin olive oil (EVOO), plus additional for drizzling
Salt and freshly ground black pepper
1 box frozen spinach, defrosted in the microwave
2 pounds ground turkey breast
1 medium onion, grated or finely chopped
3 cloves garlic, grated or finely chopped
1 large egg
3/4 cup (3 handfuls) bread crumbs
1/2 cup (2 palmfuls) grated Parmigiano Reggiano cheese
2 tablespoons butter
2 heaping tablespoons flour
1 cup milk
1 cup chicken stock
1/2 teaspoon freshly grated nutmeg (eyeball it)
4 hero rolls
1 10-ounce sack shredded provolone cheese
Preheat oven to 400F.
Toss the tomatoes and onions with the chopped parsley, vinegar, about 2 tablespoons of EVOO, salt and pepper. Let stand while you prepare dinner.
Wring defrosted spinach dry in a clean kitchen towel. Place turkey in a bowl and make a well in the middle of it. Into the well, add the grated onion and garlic, egg, bread crumbs, grated Parmigiano, spinach, salt and pepper.
Form into 12 large balls and arrange on a nonstick cookie sheet. Drizzle the meatballs with EVOO, about 1/4 cup, and roast for about 20 minutes, or until cooked through.
While meatballs are in the oven, heat a small sauce pot over medium heat with 2 tablespoons butter. When butter is melted, whisk in flour, cook for 1 minute, then whisk in the milk and chicken stock. Bring liquid up to a boil and simmer until thickened. Season the sauce with salt, pepper and nutmeg, turn down to low.
Split the rolls in half lengthwise and scoop a little bit of the bread out, so there is more room for the meatballs and sauce. Transfer to a baking sheet and put in the oven cut side up, and toast until golden brown.
Place 2-3 balls on each toasted roll, top with some of the white sauce and the provolone cheese. Place back in the oven or under the broiler to melt the cheese. Serve the tomato and onion salad alongside.