Wash and dry all produce. Heat Guide for Step 6: 1/4 tsp mild, 1/2 tsp medium and 1 tsp spicy! Add 10 cups water and 2 tsp salt to a large pot. (NOTE: Use same for 4 ppl.) Cover and bring to a boil over high heat. Add linguine to the pot of boiling water. Cook uncovered, stirring occasionally, until tender, 10-12 min. When pasta is tender, reserve 1/4 cup pasta water (dbl for 4 ppl), then drain pasta. Return pasta to the same pot, off heat.

While pasta cooks, peel, then mince or grate the garlic. Halve, peel, then cut half the onion into 1/4-inch pieces (whole onion for 4 ppl). Drain and rinse the shrimp, then pat dry with paper towels. Toss the shrimp with half the Italian Seasoning in a medium bowl. Season with salt and pepper.

Heat a large non-stick pan over medium heat. When hot, add 1 tbsp oil (dbl for 4 ppl), then half the garlic and 1/4 tsp chili flakes (dbl for 4 ppl). Cook, stirring often, until fragrant, 1-2 min. Carefully transfer to a small bowl and set aside.

Heat the same pan over medium-high heat. Add 1/2 tbsp oil (dbl for 4 ppl), then the shrimp. Cook, stirring occasionally, until the shrimp just turns pink, 1-2 min.\*\* Transfer shrimp to a plate. Add the onions to the same pan. Cook, stirring occasionally, until the onions soften, 2-3 min.

Add the crushed tomatoes, reserved pasta water, remaining garlic and remaining Italian Seasoning to the pan with the onions. Cook, stirring occasionally, until sauce thickens slightly, 3-4 min. Remove pan from heat. Add spinach and shrimp. Stir, until spinach is wilted, 1-2 min. Season with salt and pepper. Pour tomato and shrimp sauce over the pasta in the large pot. Toss to combine.

Divide shrimp diavolo between plates. Drizzle a 1/4 tsp garlic-chili oil over each plate. (NOTE: Reference the Heat Guide). Sprinkle Parmesan cheese over top.