In a large skillet, heat a tablespoon of olive oil over medium heat. Add the chopped yellow onion and cook for 5-7 minutes until softened and translucent. Add the minced garlic and jalapeño, cooking for another 1 minute until fragrant. Remove from heat.

Place the boneless, skinless chicken breasts in the bottom of your 6-quart slow cooker. Add the sautéed onion mixture, rinsed and drained Great Northern beans, cannellini beans, undrained diced green chilies, and chicken broth to the slow cooker.

Stir in the chili powder, ground cumin, dried oregano, salt, and black pepper. Stir gently to combine all ingredients.

Cover the slow cooker and cook on LOW for 6-8 hours, or on HIGH for 3-4 hours, until the chicken is thoroughly cooked and easily shreds with a fork.

Carefully remove the cooked chicken breasts from the slow cooker and shred them using two forks. Return the shredded chicken to the slow cooker.

Add the softened, cubed cream cheese and half-and-half (or heavy cream) to the slow cooker. Stir well until the cream cheese is completely melted and smoothly incorporated into the chili, creating a creamy base.

In a small bowl, whisk together the cornstarch and cold water to form a smooth slurry. Pour this slurry into the slow cooker, stirring constantly to avoid lumps.

Cover the slow cooker and continue to cook on HIGH for an additional 15-30 minutes, or until the chili has thickened to your desired consistency.

Taste and adjust seasonings as needed, adding more salt, pepper, or spices if desired. Ladle the hearty white chicken chili into bowls and serve hot with your favorite toppings such as fresh cilantro, shredded cheese, a dollop of sour cream, diced avocado, or crunchy tortilla strips. Enjoy!