In a medium bowl, combine the lettuce, micro-greens, tomatoes, cucumbers, onion, blueberries and Feta cheese. Toss and refrigerate until ready to serve.
In a small bowl, combine the olive oil, lemon juice, vinegar, salt, pepper and basil. Mix well and refrigerate until ready to serve.
Just before serving, drizzle the dressing over the salad and toss.