Adjust rack to top position and preheat oven to 425 degrees. Bring a large pot of salted water to a boil. Wash and dry produce.

Halve, peel, and dice onion into ½-inch pieces; mince a few pieces until you have 2 TBSP (4 TBSP for 4 servings).

In a large bowl, combine beef*, minced onion, panko, stock concentrate, half the Parmesan, half the Italian Seasoning, 1 TBSP water (2 TBSP for 4 servings), salt (we used ½ tsp; 1 tsp for 4), and pepper. Form into 8-10 1-inch meatballs (16-20 meatballs for 4).

Place meatballs on a lightly oiled baking sheet. Roast on top rack until browned and cooked through, 14-16 minutes.

Once water is boiling, add spaghetti to pot. Cook, stirring occasionally, until al dente, 9-11 minutes. Reserve 1 cup pasta cooking water, then drain. 

Heat a drizzle of olive oil in a large pan over medium heat. Add diced onion; cook until browned and softened, 2-4 minutes. Add crushed tomatoes, garlic powder, remaining Italian Seasoning, ¼ cup reserved pasta cooking water (ladle straight from the pot if pasta isn’t finished cooking yet), ¼ tsp sugar, salt, and pepper (for 4 servings, use ½ cup pasta cooking water and ½ tsp sugar). Cook until sauce has slightly thickened, 4-6 minutes more.

Reduce heat to low; cover and simmer until pasta and meatballs are finished cooking.

Add drained spaghetti and cooked meatballs to pan with sauce; toss to coat. (For 4 servings, if your pan isn’t large enough, carefully pour everything back into the empty pasta pot.) TIP: If needed, stir in more reserved pasta cooking water a splash at a time until everything is thoroughly coated in sauce.

Taste and season with salt and pepper.

Divide pasta and meatballs between shallow bowls. Top with remaining Parmesan and serve.