Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper. Rinse 1 cup of quinoa under cold water and drain.

Combine the rinsed quinoa with 2 cups of water in a saucepan and bring to a gentle boil. Reduce heat to low, cover and simmer for about 15 minutes or until water is absorbed. Let sit covered for 5 minutes.

Place mackerel fillets on the baking sheet, drizzle with olive oil, season with salt and pepper, and bake for 15-20 minutes until flaky.

Finely chop ingredients: dice cherry tomatoes, cucumber, slice red onion, and chop parsley.

Whisk together lemon juice, olive oil, and capers in a small bowl. Season with salt and pepper to taste.

In a large bowl, combine quinoa, chopped vegetables, and flaked mackerel. Toss gently to mix.

Drizzle lemon-caper dressing over the salad and toss gently. Let sit for a few minutes before serving.