Place a medium pot or wide skillet over medium-high heat and add the marinara sauce. Bring to a simmer.
While sauce heats up, place the cashews and chicken broth in a high-speed blender and pulse until creamy. Add ¼ cup heaping cup of the cashew cream to the marinara sauce and stir well to combine. Reserve anything extra for future recipes.
Add the chicken to the sauce and stir well to combine, cooking for 5 minutes or until chicken heats up. Taste the sauce and if it needs more salt or pepper, add as needed.