Bring a couple inches of water to boil in a large skillet and add the florets, orange rind and salt. Cover and simmer until tender, about 6 minutes. Drain broccoli and cauliflower, remove rind and transfer to a platter or bowl. Return pan to heat, add extra-virgin olive oil and heat over medium heat. Add shallots and cook until soft, 3 to 4 minutes. Add broccoli and cauliflower and turn to coat. Squeeze the orange juice over the pan and toss veggies again. Season the orange scented broccoli and cauliflower with salt and pepper, to your taste. Garnish with sliced scallions.