Chop the chicken into bite-sized pieces and dice the celery and zucchini. Mince the garlic and keep all ingredients nearby for quick assembly.
Heat the large pot over medium heat and add a splash of olive oil. Sauté the garlic and diced celery until fragrant and slightly translucent, about 3-4 minutes, with a gentle sizzle filling the air.
Add the chicken pieces to the pot, season with salt and pepper, and cook until they turn white and start to brown slightly, about 5-6 minutes. You should hear a light sizzle as they cook.
Pour in the chicken broth and bring the mixture to a gentle simmer. Add the diced zucchini and red pepper flakes, if using, then reduce the heat to medium-low.
Let the soup simmer gently for about 10 minutes, until the vegetables are tender and the chicken is cooked through. The broth will become fragrant and slightly thickened.
Check the seasoning and adjust with more salt, pepper, or a squeeze of lemon if desired. Stir in the cream cheese or heavy cream to add richness and create a smooth, silky broth.
Allow the soup to sit for a minute or two, then taste again and adjust seasoning if needed. The soup should be warm, fragrant, and inviting, with tender vegetables and flavorful chicken.
Serve the hot soup in bowls, garnished with fresh herbs if desired. Enjoy this comforting, keto-friendly meal that feels like a warm hug.
