In a large pot, heat the olive oil over medium heat. Add the finely chopped onion and sauté until it becomes translucent, about 3-4 minutes. This step builds the aromatic base for your soup.
Pour in the chicken broth and bring it to a gentle simmer. Stir in the dried parsley and thyme, allowing the flavors to meld together.
Add the cauliflower rice to the pot. If you’re using frozen cauliflower rice, there’s no need to thaw it first. Just stir it in, and let it cook for about 5-7 minutes, or until tender.
Add the diced leftover chicken to the pot, stirring to combine. Allow it to heat through, which should take another 5 minutes.
In a separate bowl, whisk together the eggs, fresh lemon juice, and lemon zest. This mixture will add a creamy texture and bright flavor to the soup.
To avoid scrambling the eggs, gradually add a ladle of hot soup to the egg mixture while whisking continuously. This process is called tempering and helps bring the eggs up to temperature.
Once tempered, slowly pour the egg mixture back into the pot, stirring continuously. This will create a luscious, silky texture in your soup. Taste and adjust the seasoning with extra lemon juice or herbs if desired. Serve warm and enjoy!