Spinach and mackerel salad

2tbsp walnut oil
2tbsp mild olive oil
2tbsp balsamic vinegar
1 ripe avocado
180g bag baby spinach
8 vine-ripened cherry tomatoes,halved
1/4 cucumber,thinly sliced
285g pack mackerel fillets,skinned and torn into bite-size pieces.

To make the dressing,whiskthe oils with the vinegar in a bowl and season.Skin and stone the avocado and cut into thin slices or cubes.Toss gently in the dressing.Wash the spinach in a large bowl of cold water.Drain and dry and pat dry with kitchen paper.Toss the spinach with the tomatoes,cucumber,mackerel,avocado and dressing,and serve with freshly ground black pepper.