Adjust rack to top position and preheat oven to 450 degrees. Bring a large pot of salted water to a boil. Wash and dry produce.

Halve, core, and thinly slice bell pepper. Trim and halve zucchini lengthwise; slice crosswise into ½-inch-thick half-moons. Trim and thinly slice scallions, separating whites from greens. Zest and quarter lemon.

Toss bell pepper and zucchini on a baking sheet with a drizzle of oil, salt, and pepper. Roast on top rack until tender and lightly charred, 15-18 minutes.

Once water is boiling, add penne to pot. Cook, stirring occasionally, until al dente, 9-11 minutes.

Reserve 1½ cups pasta cooking water (2 cups for 4 servings), then drain. (Keep empty pot handy for next step.)

Heat a drizzle of olive oil in pot used for pasta over medium heat. Add scallion whites and 1 tsp Tuscan Heat Spice (2 tsp for 4 servings); cook, stirring, 1 minute. (Be sure to measure the Tuscan Heat Spice; we sent more.)

Whisk in cream sauce base, stock concentrate, and ¼ cup reserved pasta cooking water (½ cup for 4). Cook, whisking, until slightly thickened, 2-3 minutes.

Reduce heat to medium low and whisk in crème fraîche until smooth.

Add drained penne, peas, half the Parmesan (save the rest for serving), half the lemon zest, 1 TBSP butter (2 TBSP for 4 servings), and a big squeeze of lemon juice to pot with sauce. Cook, stirring, until butter has melted and penne is coated in a creamy sauce. TIP: If needed, stir in more reserved pasta cooking water a splash at a time.

Stir in roasted veggies. Taste and season with salt and pepper. Add more lemon zest or lemon juice if you like. TIP: For an extra-rich experience, stir in another 1 TBSP butter (2 TBSP for 4).

Divide pasta between plates or shallow bowls. Top with scallion greens and remaining Parmesan. Serve with any remaining lemon wedges on the side.