Prep the Components : Pat the shrimp thoroughly dry with paper towels and place in a medium bowl. Zest the entire lemon over the shrimp, then cut the lemon in half and set aside. Chop the dill. Ensure all other ingredients are measured and ready.
Flash-Sear the Shrimp : Heat the avocado oil in the Dutch oven over high heat until it shimmers. Carefully arrange the shrimp in a single layer and sear for 60-90 seconds per side, just until they turn pink and develop a slight crust. Do not cook through. Using a slotted spoon, transfer the seared shrimp to a clean plate.
Sauté the Aromatics : Reduce the heat to medium. Add the sliced shallots to the same Dutch oven and cook, stirring frequently, until they soften and become translucent, about 3-4 minutes. Add the minced garlic and smoked paprika, cooking for another minute until fragrant.
Wilt the Greens : Pour in the white wine to deglaze the pan, scraping up any browned bits from the bottom. Add the spinach to the pot in large handfuls, along with ½ teaspoon of the sea salt. Stir continuously until all the spinach has wilted down, which should take 4 to 6 minutes.
Form the Pan Sauce : Reduce the heat to low. Squeeze the juice from the reserved lemon halves into the spinach. Stir in the unsalted butter, black pepper, cayenne, and the remaining ¼ teaspoon of salt until the butter is fully melted and a cohesive sauce forms.
Combine and Finish : Return the seared shrimp and any accumulated juices to the pot. Gently fold everything together and allow the shrimp to warm through and finish cooking, about 2-3 minutes. The shrimp are done when they are opaque and curl into a 'C' shape.
Plate and Garnish : To serve, create a bed of the garlicky spinach on each plate and arrange the shrimp on top. Drizzle with any remaining pan sauce and sprinkle generously with the fresh dill.