In a medium saucepan, bring 2 1/2 cups water, the butter and 1 teaspoon salt to a boil over medium-high heat. Once the water is boiling, add the couscous. Return the water to a boil, then reduce the heat to medium-low and cook, uncovered, for 8 minutes. Turn off the heat, cover the saucepan and let sit for 5 minutes. Fluff with a fork.
Add the basil, chives, parsley, olive oil, dill, lemon zest and juice to a large bowl. Add the cooked couscous and toss to combine. Season with salt and pepper, toss to combine.