Heat the olive oil in a medium pot over medium heat. Add the celery, onion, and apple. Cook, stirring occasionally, for 5-6 minutes. Transfer to a bowl.
In a liquid measuring cup, whisk together the water, collagen hydrolysate, and poultry seasoning.
Return the pot to medium heat and add the rice and water mixture. Bring to a boil. Reduce heat to low, cover, and simmer until the water is absorbed and the rice is tender, 30-40 minutes (or as indicated on rice package).
When done, fluff the rice with a fork. Add the dried cranberries, pumpkin seeds, and parsley. Mix gently to combine. Season to taste with salt.
Serve immediately or, to make ahead, transfer to a baking dish and cool to room temperature. Cover and refrigerate for up to 3 days.
To reheat, cover with aluminum foil and bake at 350ºF for 20 minutes.