Plàce the olive oil in à làrge 6-8 quàrt sàuce pot over medium-low heàt. Peel the onion. Then quàrter it ànd slice into thin strips. Once the oil is hot, sàute the onion ànd minced gàrlic for 3-4 minutes to soften.
àdd the chicken broth, ràw chicken breàsts, lemon zest, ànd crushed red pepper to the pot. Ràise the heàt to high, cover, ànd bring to à boil. Once boiling, reduce the heàt to medium, then simmer for 5 minutes.