Avocado-stuffed Portobello Mushrooms

Ingredients

 * 8 small or 4 large portobello mushrooms
 * 2 tbsp butter
 * 2 leeks, sliced
 * 1 garlic clove, pressed
 * 2 large California avocados, peeled and chopped
 * 1 tsp chopped fresh or dried rosemary
 * 1 tbsp lime juice
 * ¼ tsp salt
 * 4 oz goat cheese
 * 3 tbsp chopped walnuts
 * 2 tbsp olive oil
 * garnish: fresh rosemary sprigs

Directions

 * 1) Remove brown gills from the undersides of mushrooms using a spoon; discard gills.
 * 2) Remove stems, if necessary, and reserve for another use, if desired.
 * 3) Melt butter in a large skillet over medium heat; add leek and garlic, and saute until tender.
 * 4) Remove from heat, and cool.
 * 5) Stir together avocado and next 3 ingredients in a medium bowl; stir in leek mixture.
 * 6) Press goat cheese evenly into mushroom caps; top evenly with avocado mixture.
 * 7) Sprinkle with walnuts, and drizzle with olive oil.
 * 8) Place on rack in a broiler pan.
 * 9) Bake at 400 °F for 5 minutes; cover loosely with aluminum foil, and bake 5 more minutes.
 * 10) Serve immediately.
 * 11) Garnish, if desired.