Combine your blackening seasoning ingredients in a small bowl.
Rinse your shrimp under cool water, drain it, and then pat it with a paper towel.
Sprinkle the blackening seasoning on the shrimp and stir to coat. Marinate the shrimp for about 30 minutes.
In a large pot, heat salted water for your pasta and bring it to a boil. Once it boils, add your pasta and cook it until it is tender.
Once tender, reserve one cup of the pasta water and drain the pasta in a colander. Set it aside.
Mince the garlic and add it to a large skillet with the butter. Heat it over a medium flame until the butter starts to foam and sizzle. Sauté the garlic in the sizzling butter for about one minute.
Add the shrimp and cook for 10 minutes until they are slightly charred and firm then remove from the large skillet.
In a skillet, add the diced tomatoes and half a cup of the pasta water.
Cook it over medium heat while stirring and let it simmer for 10 minutes until it is slightly thickened. Add ¼ teaspoon of salt.
Add the cooked pasta to the skillet and toss it to combine with the sauce then add the shrimp and stir to combine.
Sprinkle the sliced green onion and chopped parsley on top. Serve with sliced lemon to squeeze over top and enjoy!