In a medium saucepan, warm the vegetable broth over medium-low heat. Keep it heated but do not let it boil.
In a large skillet, combine the olive oil and 2 tablespoons of butter. Heat over medium heat until the butter has melted and begins to bubble gently.
Add the finely chopped onion to the skillet and sauté for about 3-4 minutes, stirring occasionally, until it becomes soft and translucent.
Incorporate the minced garlic into the skillet and cook for an additional minute, stirring constantly until fragrant and lightly golden.
Introduce the Arborio rice to the skillet. Stir well to coat the rice grains evenly with the buttery mixture and toast them for about 2 minutes.
Gradually add 1 cup of the warm vegetable broth to the rice, stirring continuously. Allow the broth to be absorbed mostly before adding more.
Continue this process of adding broth in 1-cup increments, each time waiting until it is mostly absorbed, stirring throughout the 18-20 minute cooking period.
While the risotto is simmering, prepare the shrimp in a separate skillet. Melt the remaining 2 tablespoons of butter over medium-high heat. Add the shrimp, seasoning with salt and pepper, then sauté for about 2-3 minutes per side until they turn pink and opaque.
Once the risotto reaches a creamy, al dente texture, remove it from heat. Stir in the grated Parmesan cheese, lemon zest, fresh parsley, and the cooked shrimp. Taste and adjust seasoning with extra salt and pepper if needed.
Allow the dish to rest for a minute before serving.
Notes
Serve in shallow bowls with extra parsley and Parmesan cheese on top.