Pat the peeled and deveined shrimp very dry with paper towels. In a medium bowl, toss the shrimp with 1 teaspoon of the olive oil, salt, black pepper, and red pepper flakes (if using). Set aside. Wash and trim the ends off the zucchini. Using a spiralizer or a julienne peeler, create noodles from the zucchini.

Heat the remaining 2 teaspoons of olive oil in a large skillet over medium-high heat until shimmering. Add the seasoned shrimp in a single layer (cook in two batches if necessary to avoid overcrowding). Cook for 1-2 minutes per side, until pink and opaque. Remove the shrimp from the skillet and set aside.

Reduce the heat to medium. Add the minced garlic to the skillet and cook for about 30-60 seconds, stirring constantly, until fragrant. Be careful not to burn it.

Pour in the chicken broth and lemon juice, scraping up any browned bits from the bottom of the pan with a wooden spoon. Bring to a gentle simmer and cook for 1 minute to reduce slightly. Stir in the butter until melted and the sauce is slightly thickened. Stir in the lemon zest.

Add the zucchini noodles to the skillet with the sauce. Toss gently with tongs for 1-2 minutes, just until they are slightly softened but still retain a slight bite (al dente). Don't overcook, or they'll become watery.

Return the cooked shrimp to the skillet with the zucchini noodles and sauce. Toss gently to combine and heat through for about 30 seconds. Taste and adjust seasoning if needed. Garnish generously with fresh chopped parsley and serve immediately.