Prep ingredients: Peel and very thinly slice 2 large garlic cloves. Grate 1⁄2 teaspoon lemon zest. Squeeze the juice from half the lemon, cut the rest into wedges. Trim ends from scallions and thinly slice on an angle. Grate cheese on large holes of a box grater, or finely chop.
Marinate shrimp: Pat shrimp dry and transfer to a medium bowl. Toss shrimp with smoked paprika, lemon zest, 3⁄4 teaspoon salt, and a few grinds pepper. Let marinate until step 5.
Make grits: In a small saucepan, bring 2 1/4 cups water and 1⁄2 teaspoon salt to a boil. Slowly stir in the quick-cooking grits. Cover, reduce heat to low, and cook, stirring occasionally to prevent sticking, until grains are tender, 6–8 minutes.
Finish grits: Remove grits from heat and stir in cheddar, scallions, and several grinds pepper. Cover to keep warm.
Sauté shrimp: Heat 3 tablespoons oil in a large skillet over high. Add shrimp and garlic, and cook, stirring occasionally, until shrimp are pink and just curled but not browned, 1–2 minutes.
Finish dish: Add spinach; toss to wilt halfway. Add lemon juice and 1⁄3 cup water and bring just to a boil. Immediately remove from heat and season to taste with salt and pepper. Stir grits, adding 1 tablespoon water to loosen if necessary. Spoon grits into shallow bowls, top with shrimp, spinach, and pan juices and drizzle with oil. Serve with lemon wedges. Enjoy!