In a medium straight-sided skillet or a large saucepan with a tight lid, heat the oil over medium heat. Add the onion and cook, stirring frequently, until soft but not browned, 8 to 10 min. Stir in the garlic and ginger and cook for 2 minutes. Add the orange juice and simmer rapidly until the liquid has almost completely evaporated, about 10 min., stirring as needed to prevent the juice from caramelizing. Add 2 cups water and bring to a boil. Remove from the heat, add the butter, couscous, and salt. Stir to combine. Cover and let stand for 15 min. With a fork, fluff the couscous. Stir in the almonds, herbs, and orange zest to taste. Season with salt and pepper to taste.