Bring a large pot of salted water to a boil. Wash and dry all produce. Trim and thinly slice scallions, separating whites from greens. Dice tomato. Quarter lemon.

Heat a large drizzle of oil in a large pan over medium-high heat. Add scallion whites, sausage, and Italian Seasoning. Cook, breaking up meat into pieces, until sausage is browned and scallions are softened, 3-5 minutes (sausage will finish cooking in step 4). Stir in tomato and cook until just softened, 1-2 minutes. Turn off heat.

Once water is boiling, gently add ravioli to pot. Reduce to a low simmer. Cook, stirring occasionally, until al dente and floating to the top, 4-5 minutes. Reserve 1/2 cup pasta cooking water (1 cup for 4 servings), then drain. TIP: Gently shake strainer with ravioli in it to remove as much moisture as possible.

Stir stock concentrate, a squeeze of lemon juice, and a small splash of reserved pasta cooking water into pan with sausage mixture. Cook over low heat until sausage is cooked through, scraping up any browned bits from bottom of pan, 1-2 minutes. Stir in sour cream and 1 TBSP butter (2 TBSP for 4 servings). Season with salt and pepper. TIP: If needed, stir in more reserved cooking water a splash at a time until sauce reaches a creamy consistency.

Carefully stir ravioli into pan with sauce. Season with salt, pepper, and lemon juice to taste.

Divide ravioli mixture between bowls. Garnish with scallion greens. Serve with any remaining lemon wedges on the side.