About 8 hours before you want to make the soup, put the wild rice and vinegar in a medium bowl and cover with water. Let sit for 8 hours and drain. 

Bring a pot of water to boil and place rice in it. Cook, according to the package directions until tender. Drain. This can be done a day or two ahead of time and the rice stored in the refrigerator. 

Place the butter in a large pot and heat over low to melt. Add the celery, carrots, onion and garlic and stir to combine. Put the lid on the pot and let the vegetables sweat for about 30 minutes over low heat.

Remove the lid and stir in the herbs and sea salt and cook for about 1 minute, until fragrant. Pour in the broth and add the chicken breasts. Increase the heat to high and bring to a boil. Turn down to medium and continue simmering for about 10 minutes until chicken is cooked through. 

Remove the chicken and cut or shred into bite-size pieces. Add the chicken back to the pot. 

Add the lemon zest and juice. 

Put the 2 tbs arrowroot in a small measuring cup with 1/4 cup of water and stir well. Add a ladle-full of the hot broth and whisk (this tempers the arrowroot so it doesn’t clump when you ad it to the soup). Slowly pour the arrowroot mixture into the pot and stir to combine. Stir in the cream and cooked rice. Season to taste with sea salt and pepper. Serve hot.