Start by mixing all the spices in a bowl. This should include the white and black pepper, garlic powder, smoked paprika, ground thyme, dried oregano, onion powder, and cayenne pepper. It’s best to have this ready beforehand; trust me, it'll save you time.

In a large skillet, heat the vegetable oil over medium heat. Once hot, add the butter and let it melt. Toss in the onion, green bell pepper, and celery. Cook until the veggies are tender. This mix is known as the "holy trinity" in Cajun cuisine and is essential for building flavor.

Sprinkle in the flour and stir well. You want to cook this mixture for about 3-5 minutes until it turns a light golden brown. That's your roux, which adds richness and thickness to the sauce.

Once the roux is ready, gently add the fresh shrimp. Stir to coat them well with the mixture. Once they start to turn pink, it’s time to add the diced tomatoes and tomato paste—these will deepen the flavors significantly.

Gradually stir in the chicken stock. This step is vital to adjust consistency. You want the sauce to be thick but still pourable. Stir continuously until everything is combined and simmer for about 10 minutes.

Once the mixture has thickened, add Worcestershire sauce, the dash of hot sauce, and salt to taste. Serve it over hot rice and garnish with sliced green onions and a pinch of cayenne. Squeeze fresh lemon juice over it to brighten everything up.