• Bring a large pot of salted water to a boil. Wash and dry produce. • Halve, peel, and dice onion. Dice mushrooms into 1/4-inch pieces. Peel and mince or grate garlic. Strip rosemary leaves from stems; finely chop leaves until you have 2 tsp (4 tsp for 4 servings). Roughly chop parsley.

• Once water is boiling, add rigatoni to pot. Cook, stirring occasionally, until al dente, 9-11 minutes. Reserve 3/4 cup pasta cooking water (11/4 cups for 4 servings), then drain.

• While pasta cooks, heat a large drizzle of oil in a large pan over medium-high heat. Add onion and mushrooms; cook, stirring occasionally, until softened, 6-7 minutes. • Add garlic, chopped rosemary, salt, and pepper; cook, stirring occasionally, until fragrant, 1-2 minutes more.

• While mushrooms cook, in a medium bowl, whisk together crushed tomatoes, flour, stock concentrates, half the vinegar, 1 cup plain water, and 3/4 tsp sugar. (For 4 servings, use all the vinegar, 2 cups water, and 11/2 tsp sugar.)

• To pan with mushrooms, add a drizzle of oil and tomato paste; cook, stirring, until tomato paste darkens, 1-2 minutes. • Add tomato-flour mixture to pan; season with salt and pepper. Bring to a boil, then reduce to a simmer. Cook, stirring occasionally, until sauce thickens, 8-10 minutes. • Stir drained rigatoni into pan with sauce, adding splashes of reserved pasta cooking water until pasta is thoroughly coated in sauce. Taste and season with salt and pepper if desired. While sauce cooks, pat chicken dry with paper towels and season with salt and pepper. Heat a drizzle of oil in a second large pan over medium-high heat. Add chicken or sausage; cook, stirring frequently, until cooked through, 4-6 minutes. Once sauce is done cooking, stir in chicken or sausage along with drained rigatoni.

• Divide pasta between bowls; top each bowl with a drizzle of olive oil. Garnish with parsley and serve. Chicken Sausage is fully cooked when internal temperature reaches 165°.