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.

Thinly slice scallions, separating whites from greens; mince whites. Zest and quarter lemon. Peel and mince or grate garlic.

In a medium bowl, combine beef*, panko, half the scallion greens, half the ketchup, 1 TBSP water, juice from one lemon wedge, salt (we used ½ tsp; 1 tsp for 4 servings), and pepper. (For 4, use all the ketchup, 2 TBSP water, and juice from two lemon wedges.)

Form into 8-10 one-inch meatballs (16-20 meatballs for 4). Place meatballs on a lightly oiled baking sheet.

Roast meatballs 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 oil in a large pan over medium-high heat. Add garlic, scallion whites, and half the lemon zest; cook, stirring, until fragrant, 30-60 seconds.

Stir in cream sauce base, stock concentrate, half the Tuscan Heat Spice (all for 4 servings), and ¼ cup reserved cooking water (½ cup for 4). Bring to a simmer, then remove pan from heat. Add 2 TBSP butter (3 TBSP for 4); taste and season with salt and pepper.

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

Divide pasta between bowls and season with pepper. Top with remaining scallion greens and remaining lemon zest to taste. Serve with a squeeze of lemon juice.