Rinse and soak the black-eyed peas overnight.
In a large pot, sauté the diced onion and minced garlic until translucent.
Add the ham hock, soaked black-eyed peas, and chicken broth to the pot.
Stir in the cayenne pepper, bay leaf, salt, and pepper.
Bring the mixture to a boil, then reduce to a simmer and cover.
Cook for 45 minutes to 1 hour, or until the peas are tender.
Remove from heat, discard the ham hock and bay leaf, and adjust the seasoning if needed.
Serve hot, garnished with fresh herbs if desired.