Slice the cucumber, dice the avocado, and halve the cherry tomatoes.
Thinly slice the red onion and chop the fresh herbs.
Add the cucumber, avocado, tomatoes, onion, and herbs to a large mixing bowl.
In a small bowl, whisk together the olive oil and fresh lemon juice.
Pour the dressing over the salad.
Gently toss until all the ingredients are evenly coated without breaking the avocado.
Serve immediately or chill for 10–15 minutes before serving for the best flavor.