Grilled shiitake mushrooms on arugula

1. Prepare the seasoning sauce by combining the soy sauce, sesame oil, olive oil, and sugar.
2. Can be prepared up to a week ahead.
3. Preheat the broiler.
4. Wash the arugula and spin dry. Clean the mushrooms and remove the stems.
5. Place them cup side up on a broiling rack.
6. Brush the seasoning sauce on the mushroom caps.
7. Position the rack 4-6 inches from the heat and broil until the mushrooms look brown and crusty, 2-3 minutes.
8. They cook very quickly, so keep an eye on them.
9. Immediately place the mushrooms on top of the arugula.
10. Pour the small amount of seasoning sauce that"s left in the pan over the arugula.
11. Sprinkle with the roasted sesame seeds and serve.