In a large stock pot bring chicken broth to a boil.
Cook orzo according to package directions. When done, drain in a mesh strainer over a bowl to reserve broth. Set aside
In a large cast iron skillet (or non stick if you don't have cast iron), heat 1 1/2 Tbsp of the olive oil over medium high heat.
Once the oil shimmers, add the shrimp in a single layer, sprinkle with salt and pepper. DO NOT STIR. Let cook 3-4 minutes on one side until crispy, then stir, cooking 1-2 minutes more or until pink. Set aside.
Add remaining 1 1/2 Tbsp oil to pan and cook the garlic and red pepper flakes about 30 seconds until fragrant.
Add the asparagus and lemon zest. Season with salt and pepper. Cook 3-4 minutes or until asparagus is deep green and softened. Add lemon juice, shrimp and pasta back to the pan.
Stir to combine and lower the heat to medium low. Add in the stock, cooking until reduced by about half and the orzo has a risotto-like texture. Adjust seasonings. Serve with fresh grated Parmesan cheese if desired.