Begin by peeling and quartering the russet potatoes. Place them in a large pot, cover with salted water, and bring to a boil over high heat. Cook for 15-20 minutes, or until the potatoes are fork-tender. Drain well, return the potatoes to the pot, and add butter. Mash until smooth, then gradually stir in milk or cream to reach your desired consistency, seasoning with salt and pepper to taste. Keep warm.

Heat a skillet over medium heat and add olive oil or butter. Once hot, sauté minced garlic for about 1 minute, stirring continuously to avoid browning. Add the large shrimp to the skillet in a single layer and cook for about 2 minutes per side, or until they turn pink and opaque. Remove the shrimp from the skillet and set aside on a plate to rest while you prepare the sauce.

In the same skillet, pour in the chicken broth and bring it to a gentle simmer, scraping up any flavorful bits from the bottom of the pan. Stir in the heavy cream, grated Parmesan cheese, and lemon juice, allowing the sauce to simmer for 3-5 minutes until slightly thickened. Taste and season with salt and pepper, and add red pepper flakes if you’re in the mood for a little heat, creating the luxurious base for your creamy garlic shrimp.

Return the cooked shrimp to the skillet, making sure they are thoroughly coated in the creamy sauce. Toss gently for about 1-2 minutes, allowing the shrimp to warm through while absorbing the flavors of the sauce. The garlic shrimp should look silky and inviting, ready to be plated over your fluffy mashed potatoes for a delightful presentation.

To serve, spoon the warm mashed potatoes onto plates, creating a lovely base for the shrimp. Top generously with the creamy garlic shrimp and sauce, allowing it to cascade over the potatoes. For a burst of freshness, garnish with chopped parsley.