Heat 2 Tbsp avocado oil in a large stockpot or deep skillet over medium heat.
If not making the Low-FODMAP version, add 1/2 yellow onion (chopped) and sauté, stirring frequently, until translucent, about 5 minutes. If making Low-FODMAP, skip this step.
If not making the Low-FODMAP version, add 3 cloves garlic (minced) and sauté, stirring, for 2 minutes. If making Low-FODMAP, skip this step.
Add 1 2/3 cups white basmati rice, 3 1/2 cups chicken broth, 1 tsp ground turmeric, 1 tsp ground cumin, 1 tsp ground ginger, 1 tsp dried thyme, 1 cinnamon stick, 1 tsp sea salt, and 1/3 cup golden raisins to the pot. Stir to combine, cover, and bring to a full boil over high heat.
Once the pot is boiling, add 1 pound raw shrimp (peeled and deveined) and stir once to distribute. Cover, reduce the heat to low, and cook gently for 20 minutes, or until the rice has absorbed the liquid and the shrimp are opaque and cooked through.
While the biryani cooks (or after, if you prefer), optionally toast 1/4 cup pine nuts in a small dry skillet over medium heat, stirring or shaking frequently, until lightly golden and fragrant; remove from heat immediately to avoid burning.
Remove the cinnamon stick, fluff the rice gently with a fork, and top with the toasted pine nuts if using. Serve hot.