Bring a large pot of salted water to a boil. Wash and dry all produce. Quarter zucchini lengthwise, then cut crosswise into 1/2-inch pieces. Halve, peel, and dice onion. Mince garlic. Strip 2 tsp thyme leaves from stems; discard stems and roughly chop leaves.

Heat a drizzle of olive oil in a large pan over medium-high heat. Add beef and cook, breaking up meat into pieces, until browned but not yet cooked through, 4-5 minutes. Season with salt and pepper.

Once water is boiling, add spaghetti. Cook, stirring occasionally, until al dente, 9-11 minutes. Carefully scoop out and reserve 1/2 cup pasta cooking water (2/3 cup for 4 servings), then drain.

Add zucchini and onion to pan with beef. Cook, stirring, until softened and beef has cooked through, about 5 minutes. Stir in garlic, chopped thyme, soy sauce, and half the Italian Seasoning (all for 4 servings). Cook until fragrant, about 30 seconds.

Add tomatoes and reserved pasta cooking water to pan. Bring to a boil, then reduce heat and let simmer until thick and saucy, about 5 minutes. Season with salt and pepper. TIP: If you have time, let the ragù simmer longer. It’ll just get better!

Add spaghetti to pan with ragù and toss to combine. Divide between plates. Sprinkle with Parmesan and chili flakes (to taste).