Start by washing your fresh asparagus under cold water to remove any dirt. Trim tough ends and cut into 2-inch pieces.

In a pot, bring water to a boil and blanch asparagus for 2-3 minutes until bright green and tender-crisp. Transfer to an ice bath.

In a large bowl, combine the blanched asparagus, halved cherry tomatoes, sliced red onion, and chopped parsley. Optionally add capers.

Flake the mackerel into bite-sized pieces and fold it into the salad gently.

Whisk together olive oil and lemon juice, season with salt and pepper, and pour over the salad, tossing it gently.

Taste the salad and adjust seasoning as needed.

Chill the salad in the refrigerator for about 10 minutes if desired.

Plate the salad and serve it immediately or store in an airtight container for up to two days.