In a large skillet over medium heat, add olive oil and sautee the onion, celery and carrots until onions are transparent, approx 10 minutes. Season with black pepper, then add the sauteed veggies to the crock pot.
Add eight cups of the chicken/turkey stock and the uncooked wild rice to crock pot.
Next stir in the chicken soup base. Set on high for 3-4 hours or low for 6-8 hours and let the crock pot do it's thing.
Once the initial cooking time is completed, you are ready to make your “roux” (for those of you who are as ignorant as I am in culinary-speak, that means the gravy-like sauce that will thicken your soup!). Melt 1/2 stick of butter in your large skillet over medium heat. Slowly whisk in the flour and cook for a minute or two. Gradually add the half-and-half or heavy cream and one cup of stock, whisking constantly until thickened and smooth (side note… directions called for “completely” smooth, which I never seem to be able to achieve… the slightly lumpy substance I end up with doesn’t seem to make a bit of difference in the quality of the finished product!)
Add the white sauce to the crock pot and stir to combine. Next add the turkey and the parsley and cook on high for another 15-20 minutes until heated through. (Another side note… if you prefer a thinner soup, add the last cup of stock. You can even add some extra water to thin it even further.) Taste and season with additional salt and pepper as desired.