Cook the quinoa according to the instructions on the packaging. This will take about 15 minutes. When the water is completely absorbed and the quinoa grains are soft, but not too mushy, turn off the heat. Loosen the grains with a fork, then add the oil and the lime juice. Rest it under cover.
Blanch the peas in boiling water for 3 minutes, rinse under cold water, drain and put aside.
Slice the radish and spring onion. Peel the avocado, chop the flesh roughly.
Drain the chickpeas.
Remove the skin from the mackerel, then flake the fish with your fingers.
Mix the yogurt with the horseradish and herbs.
In a mixing bowl, combine the peas, quinoa, chick peas, radishes and spring onions. Season with salt and pepper. Gently rotate the fish into salad.
Serve with the horseradish sauce.