Combine the rice, water, and 1/2 teaspoon salt in a saucepan. Bring the mixture to a boil, and then cover the pot, reduce the heat to low, and let the rice simmer for about 40 minutes or just until tender. Remove it from the heat. NOTE: you can prepare the rice a day ahead of time if desired.
While the rice is cooking, slice the leek into thin rings. Chop the apple into 1/2-inch cubes, and dice the celery.
Heat the olive oil in a saute pan over medium-high heat, and add the leek, apple, and celery. Saute for 8-10 minutes or until the leek turns golden.
When the rice is nearly cooked, preheat the oven to 325°F.
In a large mixing bowl, combine the cooked apples and vegetables with the poultry seasoning, bread cubes, pistachios, cranberries, and cooked rice. Toss everything well to combine.
Add the chicken stock to moisten everything. You may need less than 3/4 cup or slightly more.
Add extra salt to taste.
Pour the stuffing into an 8x8 casserole dish. Cover lightly with foil, and bake the stuffing for about 20 minutes . Remove the foil for the last 10 minutes to allow the bread to get toasty.