I melt the butter or oil in my dutch oven over medium heat, then toss in the diced onion, carrots, and celery along with a pinch of salt and pepper. I let these cook for about 5 minutes, stirring occasionally, until they start to soften and the onion turns translucent. This step builds the flavor foundation for the entire soup.
Next, I stir in the diced mushrooms and minced garlic, cooking everything for another 5 minutes. The mushrooms release their moisture and start to brown slightly, which adds a deeper, savory flavor. The garlic only needs a minute or two before it turns fragrant.
I pour in the turkey stock or chicken broth, then add the thyme, parsley, and fish sauce. I give it a good stir to combine everything, making sure the dried herbs are evenly distributed through the liquid before it starts to heat up fully.
This is where I add the wild rice directly into the simmering broth. I stir it in well so it's fully submerged, since wild rice needs plenty of liquid contact to cook evenly and become tender over time.
I let the pot simmer uncovered for about 30 to 45 minutes, checking occasionally. Wild rice takes longer than white rice, so I taste a few grains around the 30-minute mark to see how much bite is left. It's ready once the grains have split open slightly.
Once the rice is nearly tender, I add the shredded turkey and let everything simmer together for another 5 to 10 minutes. This warms the turkey through without overcooking it, keeping the meat tender rather than dry and stringy.
Before serving, I always taste the soup and adjust the salt and pepper. Since broth saltiness varies by brand, I find this final taste-check step makes a real difference in the finished flavor.