1. In a large saucepan (a heavy cast-iron skillet works best) over high-medium heat, add the olive oil and tomatoes. Season with salt and pepper to taste. Allow the tomatoes to cook for 3 to 5 minutes, add the shallots and garlic and toss. Cook for another 2 to 3 minutes, until tomatoes start to blister. Set aside.
2. Using the same skillet add the shiitake mushrooms and cook for about 5 to 8 minutes, or until lightly browned. Add corn and cook for 3 to 5 minutes. Combine with tomatoes.
3. In a medium pot, prepare the couscous according to directions on the package, using the necessary amount of vegetable broth instead of water. Fluff couscous with a fork and carefully combine with vegetables.
4. Transfer to a platter and top with basil. Drizzle some olive oil and serve.