Place the peeled and quartered potatoes in a large pot. Cover with cold water by about an inch. Add a generous pinch of salt. Bring to a boil, then reduce heat and simmer for 15-20 minutes, or until potatoes are fork-tender.

Drain the potatoes thoroughly. Return them to the hot pot over low heat for 1-2 minutes, shaking occasionally, to dry out any remaining moisture.

Remove from heat. Add the warmed milk, softened butter, salt, and pepper to the pot. Mash with a potato masher or ricer until smooth and creamy. Taste and adjust seasoning as needed. Cover to keep warm.

Pat the shrimp dry with paper towels. Season with 1/4 tsp salt and 1/8 tsp pepper.

Heat olive oil and 1 tbsp butter in a large skillet over medium-high heat. Once butter is melted and shimmering, add the shrimp in a single layer (cook in batches if necessary to avoid overcrowding). Cook for 1-2 minutes per side until pink and opaque. Remove shrimp from the skillet and set aside.

Reduce heat to medium. Add the remaining 1 tbsp butter to the skillet. Add minced garlic and red pepper flakes (if using) and sauté for 1 minute until fragrant, being careful not to burn the garlic.

Pour in the white wine (if using) and deglaze the pan, scraping up any browned bits from the bottom. Let it simmer for 1-2 minutes until slightly reduced.

Stir in the heavy cream and bring to a gentle simmer. Cook for 3-5 minutes, stirring occasionally, until the sauce thickens slightly.

Remove the skillet from heat. Stir in the Parmesan cheese and fresh lemon juice. Taste the sauce and adjust salt and pepper if needed.

Return the cooked shrimp to the skillet and toss gently to coat them in the creamy garlic sauce.

Divide the warm mashed potatoes among serving plates.

Spoon a generous portion of the creamy garlic shrimp over the mashed potatoes.

Garnish with fresh chopped parsley. Serve immediately.