Layer peaches, strawberries and blueberries on a platter or bowl.
In a bowl place orange juice, sugar, vinegar, mustard, olive oil and salt. Use an immersion blender and blend until it thickens some. (You can use a blender if you don’t have an immersion blender.)
Pour dressing into a small jar or dish and sprinkle with the poppy seeds and stir.
Lightly pour over fruit. You may not need to use all the dressing.
Place mint leaves around to garnish. Serve immediately.
Notes
You can prep and assemble the fruit and make the dressing the day before you plan on serving this fruit salad, but store them separately in the refrigerator to keep the fruit from getting soggy.
Leftovers can be stored in an airtight container in the refrigerator for up to 3 days.