Prepare the Mashed Potatoes:

1. Place cubed potatoes in a large pot and cover with cold, salted water by 1 inch.
2. Bring to a boil over high heat, then reduce to medium-high and cook for 15-18 minutes until fork-tender.
3. Drain potatoes thoroughly and return to the hot pot for 1 minute to evaporate excess moisture.
4. Add butter and mash until completely incorporated.
5. Gradually add warm milk, mashing to desired consistency.
6. Fold in sour cream, salt, and pepper. Cover and keep warm.

Cook the Shrimp:

1. Pat shrimp completely dry with paper towels and season with salt, pepper, and paprika.
2. Heat olive oil in a large skillet over medium-high heat until shimmering.
3. Add shrimp in a single layer (cook in batches if necessary) and cook for 2-3 minutes per side until pink and opaque.
4. Remove shrimp to a plate and set aside.

Make the Garlic Cream Sauce:

1. In the same skillet, reduce heat to medium and add 2 tablespoons butter.
2. Add minced garlic and sauté for 30 seconds until fragrant but not browned.
3. Deglaze with white wine, scraping up any browned bits from the bottom of the pan.
4. Pour in heavy cream and bring to a gentle simmer. Cook for 3-4 minutes until slightly thickened.
5. Whisk in Parmesan cheese until melted and smooth.
6. Add lemon juice, remaining 2 tablespoons butter, and red pepper flakes if using.
7. Return cooked shrimp to the pan and toss gently to coat. Heat through for 1 minute.
8. Remove from heat and stir in fresh parsley.

To Serve:

1. Spoon warm mashed potatoes into shallow bowls, creating a well in the center.
2. Arrange shrimp over potatoes and generously spoon the garlic cream sauce over everything.
3. Garnish with additional parsley and a light dusting of paprika.
4. Serve immediately while hot.