In a medium bowl, whisk together olive oil, balsamic vinegar, Dijon Mustard, salt, and pepper until creamy. Set aside or transfer to fridge until you are ready to serve.
In a large salad bowl, toss together romaine and arugula. Top with peaches, avocado, tomatoes, onion, cucumbers, almonds, and goat cheese. Toss with desired amount of dressing and serve immediately.