Steam the cauliflower florets in a steamer basket over boiling water until very tender, approximately 10 to 12 minutes.
While the cauliflower is steaming, heat half of the olive oil in a large non-stick skillet over medium-high heat.
Season the salmon fillet with salt and pepper, then place it in the skillet skin-side up and sear for 4 to 5 minutes.
Flip the salmon and cook for another 4 to 5 minutes until the fish is golden on the outside and flakes easily with a fork.
Remove the salmon from the skillet and set aside to rest.
In the same skillet, add the remaining olive oil along with the green beans and minced garlic.
Sauté the green beans for 5 to 7 minutes until they are bright green and tender-crisp.
Drain the steamed cauliflower and place it in a food processor or use a hand masher to blend until smooth and creamy, adding salt and pepper to taste.
Spoon the cauliflower mash onto a plate, top with the seared salmon, and serve the garlic green beans on the side with a fresh squeeze of lemon juice.