Begin by placing peeled and diced russet potatoes in a large pot of salted boiling water. Cook for 15–20 minutes until fork-tender. Drain and return to pot. Add butter and milk, then mash until creamy, seasoning with salt and pepper.

In a large skillet over medium-high heat, add oil and heat. Once shimmering, add seasoned shrimp and cook for 2–3 minutes per side until pink and opaque. Remove from skillet and set aside.

In the same skillet, add more oil if needed. Place salmon filets skin-side down and sear for about 4–5 minutes. Flip and cook another 4–5 minutes until flaky. Remove from skillet.

In the same skillet, melt butter over medium heat. Sauté minced garlic for 1–2 minutes. Add heavy cream, Dijon mustard, and season. Simmer for 4–5 minutes until slightly thickened.

Return shrimp and salmon to the skillet, spooning the garlic cream sauce over them. Simmer for another 2–3 minutes.

In a separate pot, boil water and cook green beans for 3–4 minutes until tender. Drain and sauté with garlic and red pepper flakes.

To serve, place mashed potatoes on a plate, top with shrimp and salmon, drizzle sauce, and serve with green beans and lemon wedges.