Cut stems from portobello mushrooms; trim and finely chop.

Mix together chopped stems, turkey, egg white, onions, garlic, soy sauce, ginger and pepper. With spoon, scrape off and discard dark gills from undersides of caps; spread turkey mixture over undersides.

In skillet large enough to accommodate portobellos in single layer, bring stock to boil; add portobellos, mixture side up, reduce heat, cover and simmer until mushrooms are tender and stuffing is fully cooked, about 15 minutes. With slotted spatula, transfer portobellos to warmed serving platter; keep warm.

Discarding solids, strain cooking liquid through fine sieve and return to skillet over high heat; cook until reduced to about 3/4 cup/175 mL.

Remove and discard hard ends of enoki mushrooms; add enokis to pan and cook just until slightly wilted, 10 to 20 seconds. With tongs, arrange over stuffed portobello caps.

Stir cornstarch with just enough water to make thin paste; stir into pan and boil for 30 seconds. Stir in sesame oil. Spoon sauce over mushrooms; garnish with coriander.

Makes 4 servings.