Prepare the couscous by mixing it with hot water, olive oil, and a pinch of salt. Cover and let it sit for 5 minutes, then fluff with a fork.

Chop the boiled octopus, tomato, yellow bell pepper, onion, mushrooms, and parsley into small pieces.

Mix the dressing ingredients: lemon juice, salt, pepper, grated ginger, grated garlic, and olive oil.

Combine the couscous, chopped vegetables, octopus, mackerel, and dressing in a large bowl. Mix well.