Meanwhile, heat a non-stick skillet over medium-low heat. Add the olive oil and swirl the pan so it is evenly coating the bottom.
When the olive oil is hot but not smoking, Add in the garlic and saute for about 30 seconds, being careful not to burn.
Add in the arrowroot starch and using a spatula (preferably a silicone head spatula) stir and toss into olive oil mixture until it is combined and there are no clumps.
Pour in the chicken broth and whisk constantly, to remove any clumping and combine evenly. Let it come to a light simmer (you may need to raise your heat to medium depending on your stovetop), it should not be boiling, just a little simmer.
Add the lemon juice, the dill, the capers, salt and pepper to taste. Continue to whisk, occasionally, until it reaches the sauce has thickened, about 5 minutes. Turn heat down to low or remove from heat if it’s getting too thick until the halibut is ready to serve.
To finish, spoon the sauce over the halibut and garnish with fresh dill. Enjoy!