Remove sausage from casings; discard casings. Heat a drizzle of olive oil in a large pan over medium-high heat. Add sausage and cook, breaking up meat into pieces, until browned and cooked through, 5-7 minutes. Turn off heat. Using a slotted spoon, transfer sausage to a paper-towel-lined plate, keeping as much oil in pan as possible.

Meanwhile, wash and dry all produce. Halve, peel, and mince shallot. Zest and quarter lemon (quarter both lemons for 4 servings). In a medium pot, combine 4 cups water (7 cups for 4) and stock concentrate. Bring to a boil, then reduce to a low simmer. (You’ll use the simmering stock in step 4.)

Heat pan with reserved oil over medium heat. Add 1 TBSP butter, shallot, salt, and pepper. Cook, stirring, until softened, 2-3 minutes.

Add 1/2 cup stock and rice to pan. Bring mixture to a simmer and cook, stirring, until liquid has mostly absorbed. Continue adding stock 1/2 cup at a time, stirring after each addition. Allow rice to absorb most of the liquid before adding more. Repeat process until rice is al dente and creamy, 25-30 minutes.

Once risotto is done cooking, stir in sausage, peas, half the Parmesan, 2 TBSP butter (3 TBSP for 4 servings), and a squeeze of lemon juice to taste. Season generously with salt and pepper.

Divide risotto between bowls. Top with lemon zest and remaining Parmesan. Serve with any remaining lemon wedges on the side.