This can be served a lovely entree/first course or even as one big salad. If you like you substitute the smoked trout with smoked salmon, but personally I think the trout is just that bit more special.
Bring a large saucepan of water to the boil. Remove the woody ends from the asparagus and cook spears in boiling water for 1-2 minutes. Refresh under cold running water and then cut the asparagus into 3cm pieces on an angle.
Break trout fillets into chunks, removing any bones. Place in a bowl, with asparagus, rocket, tomatoes, avocado, parsley and cucumber.
For the dressing mix together the lemon juice, mustard, salt and pepper. Add the olive oil and whisk well.
Toss the salad together with the dressing and serve.