Start by heating a large skillet over medium-high heat until shimmering, then add 1 tablespoon of olive oil, swirling to coat the bottom.
Add the shrimp to the pan in a single layer. Cook for 2-3 minutes, stirring or flipping occasionally, until they turn a bright pink and are just opaque. Remove the shrimp and set aside.
In the same skillet, add another teaspoon of olive oil if needed, then toss in the chopped asparagus pieces. Sauté for 4-5 minutes, stirring often, until they are tender-crisp and slightly charred at the edges.
Add the minced garlic to the asparagus and cook for about 30 seconds until fragrant, being careful not to burn it.
Return the cooked shrimp to the skillet. Zest the lemon directly over the ingredients, then squeeze in the juice of half the lemon. Toss everything gently to combine and coat in the lemon-garlic oil.
Cook for another minute until everything is heated through and flavors meld. Season with salt, pepper, and red pepper flakes if using.
Transfer the dish to a serving plate, drizzle with a little extra olive oil if desired, and squeeze over additional lemon juice for brightness. Serve immediately while hot.
