Bring a large pot of water to a boil and place a steamer basket inside.
Add the cauliflower florets to the basket, cover, and steam for about 10-12 minutes or until very tender.
Add the green beans to the steamer basket during the final 5 minutes of the cauliflower cooking time.
Transfer the steamed cauliflower to a food processor or blender along with the garlic, Greek yogurt, and a pinch of salt and pepper.
Pulse the cauliflower mixture until it reaches a smooth, creamy consistency.
Pat the salmon fillet dry with a paper towel and season both sides with salt and pepper.
Heat the olive oil in a non-stick skillet over medium-high heat until shimmering.
Place the salmon in the pan, skin-side down, and sear for 4-5 minutes until the skin is crisp.
Flip the salmon carefully and cook for another 2-3 minutes until the fish is cooked through to your preference.
Serve the seared salmon over the garlic cauliflower mash with the steamed green beans on the side, finishing with a squeeze of fresh lemon juice.