In a small bowl, whisk together the lemon juice, lemon zest, minced garlic, chopped parsley, and dill to create the dressing.
Steam the broccoli florets for 3-4 minutes until tender-crisp and bright green.
In a medium bowl, toss the steamed broccoli and rinsed chickpeas with half of the prepared lemon-herb dressing to create a vibrant mix.
Pat the mackerel fillets dry with a paper towel and season both sides with sea salt and black pepper.
Heat the olive oil in a non-stick skillet over medium-high heat.
Place the mackerel fillets in the pan, skin-side down, and sear for 3-4 minutes until the skin is crispy and golden.
Flip the fillets and cook for another 1-2 minutes until the fish is opaque and flakes easily.
Plate the chickpea and broccoli mix, top with the seared mackerel, and drizzle with the remaining dressing.
Optionally, flake the mackerel with a fork and toss it directly into the medley for a complete mackerel mix.