Cut zucchini into spirals or noodle strands using the vegetable spiralizer or julienne peeler. Set aside noodles.
Heat large pan on medium-high heat. Melt 2 Tablespoons butter/olive oil, then add minced garlic and shrimp. Cook shrimp until pink and cooked through. Don't let the garlic burn.
Add zucchini noodles and cook until tender, about 3-5 minutes. Zucchini noodles cook really fast, so taste a strand as you cook and decide how firm or "al-dente" you want the zucchini. Don't overcook the zucchini noodles or else they'll become mush.
Remove the pan from the heat, add 3/4 cup parmesan cheese, squeeze some lemon juice and season generously with salt and pepper to taste. Add chili flakes then serve warm with optional lemon wedges.