Prepare the chicken- Bring a medium pot of water to a boil over high heat. Add chicken breasts to the boiling water and return to a rolling boil. Allow chicken breasts to simmer for 5 minutes then cover the pot with a tight-fitting lid and remove from heat. Allow chicken to poach in the boiled water for approximately 30 minutes.
Meanwhile, add the diced potatoes to a pot and cover with cold water by at least two inches. Bring water to a boil and cook potatoes until fork tender. Remove from heat, drain, and rinse with cold water to stop cooking. Transfer to a large mixing bowl.
Remove the cooked chicken from the pot of water and chop into small bite-size cubes. Transfer to the large mixing bowl with the potatoes.
To the same bowl as the chicken and potatoes add the celery, green onion, jalapeño, red bell pepper, and red grapes. Gently toss to combine.
In a separate, smaller bowl, whisk together the mayonnaise, apple cider vinegar, cajun seasoning, sweet paprika, and salt and pepper. Transfer mayonnaise mixture to the potato mixture and toss to combine. Season with additional salt and pepper, to taste and garnish with fresh chopped parsley if desired.
Assemble meal prep bowls- Divide chicken and potato salad between meal prep containers and top each with one hard-boiled egg, if desired. Serve with fresh fruit, carrot sticks, and crackers, or any other foods that store well in the refrigerator for 3-4 days.