Bring a large pot of salted water to a boil. Wash and dry produce.

Trim and thinly slice scallions, separating whites from greens. Trim and halve Brussels sprouts lengthwise; lay flat and thinly slice crosswise into shreds. Peel and mince or grate garlic. Zest and quarter lemon.

Melt 1 TBSP butter in a large pan over medium-high heat. (For 4 servings, use 2 TBSP butter and a large high-sided pan or Dutch oven.) Add almonds and as many chili flakes as you like. Cook, stirring, until golden and toasted, 2-3 minutes.

Turn off heat; stir in scallion whites. Season with salt and pepper.

Transfer to a small bowl. (TIP: Be sure to include any butter as well!) Wipe out pan.

Heat a large drizzle of olive oil in pan used for almonds over medium-high heat. Add Brussels sprouts; season with salt and pepper. Cook, stirring occasionally, until bright green and slightly softened, 3-5 minutes.

Add garlic and cook until fragrant, 30-60 seconds more. TIP: Add another drizzle of olive oil if pan seems dry.

Once water is boiling, add linguine to pot. Cook, stirring occasionally, until al dente, 1-3 minutes.

Reserve 1 cup pasta cooking water (2 cups for 4 servings), then drain.

Once linguine is drained, return pan with Brussels sprouts to stovetop over medium heat. Add cream sauce base and ½ cup reserved pasta cooking water (1 cup for 4). Cook, stirring, until slightly thickened, 2-3 minutes.

Turn off heat.

To pan with sauce, add scallion greens, lemon zest, drained linguine, half the Parmesan, 1 TBSP butter (2 TBSP for 4 servings), and a big squeeze of lemon juice. Toss until butter has melted and pasta is coated in a creamy sauce, about 1 minute. TIP: If needed, stir in more reserved pasta cooking water a splash at a time.

Taste and season with salt and pepper. Add more lemon juice if desired.

Divide pasta between bowls. Top with spicy almonds (and any leftover butter!) and remaining Parmesan. Serve with any remaining lemon wedges on the side.