Bring 1 cup of water and sea salt to a boil in a small saucepan.
Whisk in the stone-ground grits, reduce heat to low, cover, and simmer for 15-20 minutes until tender.
While grits cook, heat olive oil in a large skillet over medium-high heat.
Add diced onion, bell pepper, and celery to the skillet, sautéing until the vegetables are softened and fragrant.
Toss the shrimp with Cajun seasoning and black pepper, then add them to the skillet.
Cook shrimp for 2-3 minutes per side until pink and opaque.
Once grits are done, remove from heat and stir in the Greek yogurt until completely smooth and creamy.
Portion the creamy grits into a bowl and top with the sautéed Cajun shrimp and vegetable mixture.
Garnish with fresh chopped parsley and serve immediately.