Pat the salmon fillet completely dry with paper towels and season both sides with sea salt and black pepper.
Heat half of the olive oil in a non-stick skillet over medium-high heat.
Place the salmon in the pan skin-side down and sear for 4 to 5 minutes until the skin is crisp and golden.
Flip the salmon and cook for another 3 to 4 minutes until cooked through to your preference, then remove from the pan to rest.
While the salmon cooks, place the rinsed cannellini beans in a small saucepan with a splash of water and heat over medium heat.
Mash the beans with a fork or potato masher until creamy and warm, seasoning with a touch of salt.
In the same skillet used for the salmon, add the remaining olive oil and minced garlic, sautéing for 30 seconds until fragrant.
Add the fresh spinach to the skillet and toss until just wilted.
Plate the creamy mashed beans first, top with the sautéed spinach, and place the seared salmon on top.
Drizzle the entire dish with fresh lemon juice before serving.