Slow-Cooker Chicken Soup

This recipe is Whole30 and low-FODMAP. I created it specifically for my son, who has sensitivities to FODMAPs so he could have a warm hearty lunch to take to school during the colder days.

Leek tips from 2 leeks (dark green parts only), chopped medium
2-3 TBS garlic-infused olive oil, divided
1 TBS tomato paste
2 tsp fresh thyme
1/8 tsp red pepper flakes
2 medium Yukon Gold potatoes, peeled and cut into bite-sized pieces
4 cups low-FODMAP chicken stock (or if you are not on a low-FODMAP diet, you can find the recipe for Overnight Chicken Stock here)
4 bone-in, skin-on chicken thighs.
2 carrots, peeled and chopped into bite-sized pieces
2 parsnips, peeled and chopped into bite-sized pieces
1 small fennel bulb, cored and chopped into bite-sized pieces
1 cup cubed butternut squash
1 12 oz chicken breast fillet
1/3 cup fresh parsley, chopped

You'll also need a large sheet of aluminum foil to make a "packet".

1. Heat 1 tablespoon of the oil over medium heat until shimmering. Add leeks and cook until softened, about 5 minutes. Add in tomato paste, thyme and red pepper flakes and cook until fragrant, about 30 seconds. Transfer contents to slow-cooker. Pour chicken broth into slow-cooker. Add bay leaves and potatoes.
2. While the leek tips cook, pat the chicken thighs dry with paper towels and season with salt and pepper. Add another tablespoon oil to the pan after removing the leeks and brown chicken thighs well on both sides (about 3 minutes per side). Transfer to a plate to let cool slightly, then discard the skin. Nestle browned chicken thighs with any accumulated juice into the slow cooker.
3. Lay out foil and put carrots, parsnips, fennel and butternut squash on one side. Toss with remaining oil and season with salt and pepper. Season chicken breast with salt and pepper and place it on top of the vegetables. Fold other half of foil over the chicken and vegetables and fold over the sides, pinching well, to form a sealed packet. Place packet into slow cooker on top of other ingredients. Cover and cook on low for 3 hours.
4. Place the foil packet on a plate. Pull out chicken breast from packet and chicken thighs from the slow cooker and place on a separate plate. Shred the meat, discarding the bones from the thighs. Add shredded chicken and vegetables from packet into the slow cooker with the fresh parsley. Season with salt and pepper to taste. Stir and serve.