Wash and dry produce.

Reserve 2 tsp Old Bay Seasoning (4 tsp for 4 servings) in a large microwave-safe bowl (you’ll use the rest in the next step). Peel and smash garlic; mince one clove (two cloves for 4). Halve, peel, and slice shallot into ½-inch-thick wedges. Dice potatoes into 1-inch pieces. Cut corn crosswise into 2-inch-thick rounds. Quarter lemon.

Rinse shrimp* under cold water; pat dry with paper towels. Season all over with salt and pepper.

Heat a drizzle of oil in a large pot over medium-high heat. Add sausage* and cook, breaking up meat into pieces, until browned and almost cooked through, 3-5 minutes. Transfer to a plate (it’ll finish cooking in the next step).

Add smashed garlic and shallot to pot; cook, stirring, until fragrant, 30 seconds.

Stir in potatoes, corn, and remaining Old Bay Seasoning. Add 4½ cups water (9 cups for 4 servings), stock concentrates, half the lemon wedges, and 1½ tsp sugar (3 tsp for 4). Cover pot and bring to a boil. Cook until potatoes are just tender, 8-10 minutes.

Once potatoes are done, stir in shrimp and sausage. Cook, stirring occasionally, making sure everything stays submerged, until sausage and shrimp are cooked through, 3-4 minutes. (TIP: Add splashes of water as needed to keep everything covered.) Turn off heat.

While shrimp and sausage cook, finely chop parsley. Halve baguette lengthwise.

Place 2 TBSP butter (4 TBSP for 4 servings) and a pinch of minced garlic in a small microwave-safe bowl. Microwave until butter is softened, 15-20 seconds. Stir in half the parsley and season with salt and pepper.

Toast baguette until golden, then spread cut sides with garlic parsley butter. Halve toasts crosswise on a diagonal.

To bowl with reserved Old Bay Seasoning, add 2 TBSP plain butter (4 TBSP for 4 servings). Microwave until melted, 30 seconds; stir to combine.

Using a slotted spoon, carefully transfer shrimp and sausage mixture (leaving broth in pot—save it for serving) to bowl with Old Bay butter. Toss to coat. Season with salt and pepper to taste.

Divide shrimp and sausage mixture between shallow bowls. Ladle ⅓ cup broth over each bowl. (TIP: Serve with more broth if you like, or save remaining for another use.) Drizzle with hot sauce to taste and sprinkle with remaining parsley. Top with a squeeze of lemon juice. Serve with garlic parsley toasts for dipping and any remaining lemon wedges on the side.