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 tomatoes. Cut lemon into wedges.

Heat 2 TBSP 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 cooked through and scallions are softened, 3-5 minutes. Stir in tomatoes and cook until just softened, 1-2 minutes. Turn off heat.

Once water is boiling, gently add ravioli to pot. Reduce heat to a simmer. Cook, stirring occasionally, until al dente and floating to the top, 4-5 minutes. Scoop out and reserve 1 cup ravioli cooking water, then drain. TIP: Gently shake your strainer with the drained ravioli in it to remove as much moisture as possible.

Stir stock concentrates, a squeeze of lemon juice, and a small splash of reserved ravioli cooking water into pan with sausage. Cook on low, scraping up any browned bits from bottom of pan. Stir in sour cream and 2 TBSP butter. Season with salt and pepper. TIP: Add more cooking water as needed to give sauce a loose consistency.

Carefully stir ravioli into pan. (TIP: If pan looks crowded, divide ravioli between bowls now and spoon sauce over.) Season with salt, pepper, and a squeeze or two of lemon juice (to taste).

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