Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Season sea scallops with salt and pepper; add to pan. Sear for 1 minute per side or until golden brown. Remove scallops; set aside. Using same pan over medium heat, carefully add 2 teaspoons olive oil and minced garlic; cook for 1 minute. Add sliced shiitake mushrooms, and cook for 1-2 minutes or until mushrooms soften and release their juices. Add oregano and thyme, and cook 1 minute more or until fragrant. Add spinach and vermouth, and cook for 30 seconds or until spinach just begins to wilt; return scallops to pan, and cook 3 minutes more. Serve.