Salmon with capers and caprese salad

Name: Salmon with capers and caprese salad
Cuisine: European, Italian, Mediterranean
Ingredients: 4 tbsp light olive oil; 2 x 250g skinless salmon; 1 tsp Dijon mustard; juice of 1/2 lemon; 2 tsp capers; 1 avocado, roughly diced; 2 ripe tomatoes, roughly; 1 ball of mozzarella, torn; small handful of basil leaves; 5og walnuts, roughly chopped