Before starting, wash and dry all produce. Add 10 cups water and 2 tsp salt to a large pot (use same for 4 ppl). Cover and bring to a boil over high heat. While water comes to a boil, cut tomatoes into 1/4-inch pieces. Thinly slice mushrooms. Zest, then juice half the lemon (whole lemon for 4 ppl). Cut any remaining lemon into wedges.

Heat a large non-stick pan over medium heat. When hot, add 1/2 tbsp oil (dbl for 4 ppl), then mushrooms. Cook, stirring occasionally, until softened, 5-6 min. Season with salt and pepper. Transfer mushrooms to a plate and set aside.

While mushrooms cook, add fusilli to the boiling water. Cook uncovered, stirring occasionally, until tender, 9-11 min.

Heat the same large non-stick pan (from step 2) over medium-high. When hot, add 1/2 tbsp oil (dbl for 4 ppl), then beef, garlic salt and Italian Seasoning. Cook, breaking up beef into smaller pieces, until no pink remains, 4-5 min.** Season with salt and pepper. Remove the pan from heat. Carefully drain and discard excess fat. Add sour cream, broth concentrate, mushrooms, 1/2 tbsp lemon juice, 1/4 tsp lemon zest (dbl both for 4 ppl) and tomatoes to the pan. Return the pan to medium-low. Cook, stirring often, until sauce thickens slightly, 1-2 min.

When fusilli is tender, reserve 2 tbsp pasta water (dbl for 4 ppl), then drain and return fusilli to the same pot, off heat. Add 2 tbsp butter (dbl for 4 ppl), reserved pasta water and spinach. Stir until butter melts and spinach wilts, 1 min.

Divide fusilli between bowls. Top with beef and creamy sauce mixture. Sprinkle Parmesan over top. Squeeze over a lemon wedge, if desired.