Add everything except the fresh tomatoes and fresh basil to the slow cooker. Stir, cover, and set cooker on low for two hours.
Stir queso occasionally during the two hours. At the end of two hours, stir in the fresh basil and tomatoes, and cook on low for an additional 15 minutes.
Keep queso in crock pot, or transfer to a glass/ceramic dish, garnish with extra basil and tomatoes, and serve with pita chips.
Enjoy with family and friends!