Before starting, preheat the oven to 425˚F.Wash and dry all produce. Add 10 cups water and 2 tsp salt to a large pot (use same for 4 ppl). Cover and bring to a boil over high heat. Roughly chop spinach.

Add spaghetti to the boiling water. Cook, stirring occasionally, until tender, 10-12 min. Reserve 1/2 cup (1 cup) pasta water, then drain and return spaghetti to the same pot, off heat.

Meanwhile, add turkey, breadcrumbs, half the Italian Seasoning, half the Parmesan and half the garlic salt to a large bowl. Season with pepper, then combine. Roll mixture into 8 equal-sized meatballs (16 meatballs for 4 ppl). Arrange meatballs on a parchment-lined baking sheet. Roast in the middle of the oven, turning halfway through, until golden-brown and cooked through, 10-12 min.**

Heat a large non-stick pan over medium-high heat. When hot, add 2 tbsp (4 tbsp) butter, then onions. Cook, stirring often, until onions soften, 2 min.

Add tomato sauce base, broth concentrate, crushed tomatoes, remaining Italian Seasoning, remaining garlic salt and reserved pasta water. Season with pepper, then stir to combine. Reduce heat to medium, then add meatballs to the pan. Cook, stirring often, until sauce thickens slightly.

Add sauce, meatballs and spinach to the large pot with spaghetti. Toss to coat, until spinach wilts, 1 min. Divide turkey meatball pasta between bowls. Sprinkle remaining Parmesan over top.