In a small bowl, combine the herbs and spices for the blackening seasoning. Rinse the shrimp under cool water, drain, and then pat dry with a paper towel. Sprinkle the blackening seasoning over the shrimp and stir to coat.

Bring a large pot of water to a boil for the pasta. Once boiling, add the pasta and cook until tender (7-10 minutes). Reserve about 1 cup of the starchy pasta water, then drain the pasta in a colander.

While the pasta is cooking, mince the garlic and add it to a large skillet with the butter. Heat the butter and garlic over a medium flame until the butter starts to foam and sizzle. Continue to sauté the garlic in the sizzling butter for about one minute. Add the shrimp and sauté until they are opaque and slightly firm (3-5 minutes), then remove them from the skillet.

Add the diced tomatoes (with juices) and about 1/2 cup of the pasta water to the skillet. Stir and cook over medium heat, dissolving the browned bits from the bottom of the skillet. Let the sauce simmer for 5-10 minutes, or until thickened slightly. Taste the sauce and add salt if needed (about 1/4 tsp).

Add the cooked and drained pasta to the skillet and toss with the sauce (add some of the remaining reserved pasta water, if needed, to loosen the pasta). Return the shrimp to the skillet and stir to combine.

Slice the green onions and chop the parsley leaves. Sprinkle both over top. Serve with sliced lemon to squeeze over top.