Heat 2 Tbsp. olive oil in large non-stick skillet over medium-high heat. Add a single layer of mushrooms and cook, without stirring, for about 5 minutes or until mushrooms become red-brown on one side. Flip and cook about 5 minutes more, until other side is same color; set aside. Sauté zucchini for about 5 minutes adding additional olive oil to skillet if necessary. Turn off heat and add corn and rice; stir to combine. Cook for an additional 3 to 5 minutes to warm ingredients. Drizzle with remaining olive oil and lemon juice and gently stir in bell pepper and thyme; season with salt and pepper. Arrange tomatoes and arugula on a plate; pour on rice mixture and top with mushrooms. May be served warm or cold. Serves 6–8.