Pick out any pebbles and rinse the black-eyed peas. Leave the black-eyed peas in a measuring cup and pour boiling water over them, they will swell slightly. Drain right before adding to the celery and onion.
In a 2 quart pot, melt the butter and saute the onion, celery, and tomato for 3-4 minutes.
Add in the dried peas and stir together with the sauteed onion, celery, and tomatoes, for about 1 minute.
Pour in 2 cups of chicken broth and 1 cup water, bring to a boil over medium-high heat. Lower heat and simmer and cover with the lid slightly ajar. Continue simmering until the broth starts to turn creamy and the beans are soft about 2 hours. Stir occasionally, and add more liquid as needed.
Next, add the canned spinach and a teaspoon of the Cajun spice blend and continue cooking for about 15-20 minutes..