Bring 1 1/4 cups vegetable broth and water to a boil in a saucepan, stir in couscous, and mix in salt and black pepper. Reduce heat to low and simmer until liquid is absorbed, about 8 minutes.

Meanwhile, heat 3 tablespoons olive oil in a large skillet over medium-high heat; stir in pine nuts and cook, stirring frequently, until pine nuts smell toasted and are golden brown, about 1 minute. Remove from heat and set aside.

Heat remaining 2 tablespoons olive oil in the same large skillet; cook and stir garlic and shallot in the hot oil until softened, about 2 minutes. Stir black olives and sun-dried tomatoes into garlic mixture and cook until heated through, 2 to 3 minutes, stirring often. Slowly pour in 1 cup vegetable broth and bring mixture to a boil. Reduce heat to low and simmer until sauce has reduced, 8 to 10 minutes.

Transfer couscous to a large serving bowl, mix with sauce, and serve topped with parsley and pine nuts.