In a bowl, whisk together the mirin, soy sauce and cornstarch. Set aside.
Coat the mahi mahi with the sesame seeds. Set aside.
In a non-stick skillet over medium-high heat, soften the peas and green onions in 1 tbsp (15 ml) of the oil. Season with salt and pepper. Set aside on a plate.
In the same skillet still over medium-high heat, cook the fish for 3 minutes in the remaining oil. Season with salt and pepper. Turn the fish and continue cooking for 2 minutes or until the desired doneness. Set aside on a plate. Wipe the skillet clean, then add the mirin mixture and cook, stirring constantly, until the sauce thickens. Return the fish to the skillet and coat with the sauce.
Serve the fish with the snap peas and, if desired, rice.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.