Wash and dry all produce. Bring 4 cups water and stock concentrate to a simmer in a small pot over mediumlow heat. Meanwhile, trim and discard bottom inch from asparagus, then cut stalks into 1-inch pieces. Halve and peel onion. Finely chop one half (save other for another use). Mince garlic. Zest, then halve lemon.

Heat a drizzle of olive oil in a large pan over medium heat. Add onion and cook, stirring, until soft, about 5 minutes. Add half the garlic and cook, stirring, until fragrant, another 30 seconds.

While onion cooks, fill a medium bowl with ice water. Lower asparagus into simmering stock. Cook until bright green, about 1 minute. Remove with a slotted spoon (keeping stock over medium-low heat) and transfer to bowl with ice water. Let cool, then drain.

Add rice to pan with onion. Cook, stirring, until grains are translucent. Add stock 1/2 cup at a time, stirring after each addition. Allow rice to absorb most of stock before adding more. Continue until grains are al dente and creamy, 25-30 minutes.

Heat a drizzle of olive oil in a medium pan over medium heat. Pat shrimp dry with a paper towel. Add shrimp, remaining garlic, and asparagus. Cook, tossing, until shrimp are opaque, 3-4 minutes. Season with salt and pepper.

When risotto is done cooking, stir in shrimp mixture, a pinch of lemon zest, half the Parmesan, and 1 TBSP butter. Season with salt, pepper, and a squeeze of lemon. Divide risotto between plates. Sprinkle with remaining Parmesan and serve.