Adjust rack to middle position; preheat oven to 425 degrees. Bring a medium pot of salted water to a boil. Wash and dry all produce. Using a fork, poke holes all over potatoes, then rub skin with a drizzle of oil, salt, and pepper. Place on a baking sheet and bake until tender when pierced with a knife, 50-60 minutes. Remove from oven.

Meanwhile, halve, peel, and dice onion. Trim zucchini, then quarter lengthwise. Cut crosswise into 1/2-inch-thick pieces. Mince or grate garlic. Heat a large drizzle of oil in a large pan over medium-high heat. Add onion and beef. Cook, breaking up meat into pieces, until browned, 4-6 minutes. Season with salt and pepper.

If needed, pour out and discard any excess fat from pan, then stir in zucchini. Cook, stirring occasionally, until slightly softened, about 5 minutes. (TIP: If pan seems dry, add another drizzle of oil.) Add garlic, tomato paste, and Italian Seasoning. Cook, stirring, until fragrant, 1-2 minutes. Add tomatoes and their liquid, stock concentrate, 1 cup water, salt, and pepper. Bring to a boil, then reduce heat to low. Cook, stirring, until slightly thickened, 3-4 minutes. Season with salt and pepper.

Meanwhile, add cavatappi to pot of boiling water. Cook until al dente, 9-11 minutes. Reserve 1 cup pasta cooking water, then drain well and return to pot. Stir in 2 TBSP butter until melted.

Stir half the ragu into pot with pasta. (TIP: If mixture seems thick, stir in reserved cooking water, 1 TBSP at a time, until saucy.) Taste and season with salt and pepper. Divide finished pasta between bowls. Sprinkle with Parmesan and chili flakes (to taste).

Once potatoes are cool enough to handle, halve lengthwise, stopping 3/4 of the way through. Gently pull potatoes open, season with salt and pepper, then divide between reusable containers. Top with remaining ragu and refrigerate overnight. Pack sour cream, cheese, and hot sauce with lunch. When ready to eat, microwave potatoes on high until heated through, 1-2 minutes. Dollop with sour cream, sprinkle with cheese, and drizzle with hot sauce (to taste).