Finely grate 1 teaspoon worth of rind from the tangerines, place in a small bowl and set aside. Use a sharp knife to slice the top and bottom from each tangerine, then remove all peel and white pith, following the curve of the fruit. Slice vertically in half, then crosswise into 1/4-inch slices. Place in a large bowl and set aside.

Add the finely chopped radishes, the chopped red onion, and lemon juice to the bowl of tangerine peel, stir to combine, and let rest for 5 minutes. Slowly whisk in the olive oil. Season to taste with salt and pepper.

Place the sliced radish, sliced onion, fennel, arugula, and mint in the bowl with the sliced tangerines. Sprinkle with salt and toss to combine. Drizzle the dressing over the salad, and toss to coat. Transfer to a serving bowl, and enjoy.