Dice the chicken breast into bite-sized pieces and season lightly with a pinch of the sea salt and black pepper.
Heat the olive oil in a large pot over medium heat and add the chicken, sautéing until golden and cooked through.
Add the diced yellow onion to the pot and cook for 3 to 4 minutes until softened and translucent.
Stir in the minced garlic, cinnamon, nutmeg, cumin, and the remaining sea salt and pepper, cooking for 1 minute until highly fragrant.
Add the cubed butternut squash and sliced carrots to the pot, then pour in the chicken broth.
Bring the liquid to a gentle boil, then reduce the heat to low, cover, and simmer for 20 to 25 minutes until the vegetables are fork-tender.
Use an immersion blender to partially blend the squash and carrots into the broth to create a thick body while keeping the chicken pieces intact.
Ladle the hot soup into a bowl and serve immediately.