In a saucepan, bring the water to a boil over high heat. Lightly salt the water, add the peas, reduce the heat to medium, and simmer until tender, 3 to 7 minutes, depending on the size and starchiness of the peas. (If peas are not in season or the fresh ones taste too starchy, you can use 1 cup frozen peas.) Remove from the heat and drain the peas, reserving the cooking liquid.

In a blender, combine the peas and about ¼ cup of the cooking liquid and purée until smooth. Add 2 tablespoons of the olive oil and process until a smooth and creamy purée forms. If it is too stiff, add a little more cooking liquid. Season to taste with salt and pepper. Spoon the warm pea purée into 4 shallow bowls and keep the purée warm while you cook the shrimp. (If you have prepared the purée ahead of time, reserve the remaining cooking liquid to add if the mixture thickens too much before serving. Reheat it gently until warm and thin as needed.)

Spread some flour in a shallow bowl. Dip the shrimp in the flour, coating evenly and tapping off the excess.

In a sauté pan, warm the remaining 2 tablespoons olive oil over medium heat. Add the garlic and sauté for a minute or two to release its fragrance; do not let it color, Add the shrimp and cook, turning once, until they turn pink, 2 to 3 minutes. Add the wine and let it bubble up. Season the shrimp with salt and pepper.

Distribute the shrimp evenly among the bowls, placing them on top of the pea purée. Garnish each portion with parsley and a drizzle of olive oil. Serve immediately.