In a medium bowl, whisk the miso into the orange juice. Whisk in the tahini, ginger, and maple syrup, and 1 tablespoon water. Stir until a drizzle-able consistency is reached, adding additional water if necessary.
Chop the broccoli into small florets. Destem and chop the greens. Thinly slice the green onion. In a large skillet, heat the olive oil over medium high heat. Add the broccoli and sauté for 2 minutes. Add the chard and green onion, and cook until the chard is wilted, about 2 minutes. Add the soy sauce and 1/4 teaspoon kosher salt and sauté for another minute, until the broccoli is bright green and crisp tender. Taste, and add another 1/4 teaspoon kosher salt if desired.
Roughly chop the artichoke. Slice the radish into matchsticks.
Place naan directly on the oven grate and pre-bake 3 to 4 minutes per side. Remove the naan from the oven and allow to cool slightly.
To serve, spread each pita with hummus. Top with greens and broccoli, artichokes, and radishes, and drizzle with the tahini miso sauce.