Giant stuffed mushrooms

4 large portobello mushrooms
2 tablespoons olive oil
1/2 teaspoon salt
ground black pepper to taste
1 clove garlic, minced
1 cup chopped fresh cilantro
1 large carrot, finely chopped
1 stalk celery, finely chopped
2/3 cup kasha (toasted buckwheat groats)
1 1/4 cups water
3 tablespoons chopped fresh parsley

1. Preheat the oven to 400 degrees F (200 degrees C).
2. Remove the mushroom stems from the caps, and set the stems aside
3. Place the caps gill side up on a baking sheet. Drizzle them with 1 tablespoon of the olive oil, and sprinkle them with salt and pepper. Roast them in the oven for 25 minutes.
4. While the mushroom caps roast, make the pilaf: cut off the dirty base from each mushroom stem and chop the stems fine.
5. In a large skillet, heat the remaining 1 tablespoon of olive oil over medium heat. Add the garlic and onion, and saute them, stirring often, until they are softened. Stir in the carrot, celery and kasha, cook 2 minutes more.
6. Add the water and the 1/2 teaspoon salt. Bring the mixture to a boil then turn the heat to low. Simmer covered for 15 to 20 minutes or until the kasha is tender, take the pan off the heat.
7. Stir in the chopped parsley and season to taste with salt and pepper. Stuff the warm caps with the pilaf and serve.