Season the Shrimp: Toss shrimp with salt, pepper, garlic powder, onion powder, cumin, and cayenne. Let marinate for 10–15 minutes.
Sear the Shrimp: Heat olive oil in a skillet over medium-high heat. Add shrimp and cook 2–3 minutes per side, until just cooked. Remove and set aside.
Sauté the Veggies: In the same skillet, add diced bell peppers. Sauté for 2–3 minutes until slightly softened. Add minced garlic and butter, cooking for another 1–2 minutes until fragrant.
Season the Base: Add the same Cajun seasoning mix (roughly 1/2 tsp each of garlic powder, onion powder, cumin, cayenne, salt, pepper) to the skillet and stir it into the butter mixture. Let toast for 30 seconds.
Cook the Noodles: Boil the Shin Ramyun noodles in a separate pot for 1 minute less than package instructions. Drain and set aside.
Make the Sauce: Pour the heavy cream into the skillet. Simmer on medium-low for 2–3 minutes, then add Parmesan cheese. Stir until melted and slightly thickened. Taste and adjust seasoning if needed.
Combine: Add cooked noodles to the sauce and toss to coat. Return shrimp to the pan and fold everything together.
Serve: Plate immediately. Garnish with parsley and a squeeze of lemon if desired.