Step 1: Cook the Pasta Boil pasta in well-salted water until just al dente. Reserve 1 cup of pasta water before draining.
Step 2: Season the Shrimp Toss shrimp with olive oil and all Cajun seasoning.
Step 3: Sear Heat a large skillet over medium-high heat. Sear shrimp 1–2 minutes per side until just cooked. Remove and set aside. Tip: Do not overcrowd the pan. Shrimp should sear, not steam.
Step 4: Build the Sauce Reduce heat to medium. Add butter and sauté shallots until softened. Add garlic and cook 30 seconds. Whisk 1 scoop bone broth collagen with ½ cup hot water until dissolved. Pour into skillet and simmer for 1 minute. Add heavy cream and Parmesan. Stir until smooth and slightly thickened.
Step 5: Emulsify Add pasta directly to the sauce. Slowly add reserved pasta water (¼ cup at a time) until glossy and creamy. This is what makes the sauce cling to the noodles.
Step 6: Finish Return shrimp to the pan. Toss gently. Add lemon juice at the end to brighten the richness. Garnish and serve immediately.