Place chicken breasts in a saucepan and cover with water or chicken broth. Bring to a boil, then reduce heat and simmer for 15-20 minutes, or until cooked through. Remove chicken, allow to cool slightly, then shred using two forks. Set aside.

In a large skillet or Dutch oven, heat olive oil over medium heat. Add the diced onion and cook until soft and translucent, about 5-7 minutes. Add the minced garlic and cook for another minute until fragrant.

Pour in the chicken broth and add the cumin, oregano, chili powder, salt, and pepper. Bring to a simmer. Add the softened cream cheese and whisk continuously until it has completely melted into a smooth, creamy sauce.

Stir in the shredded chicken, rinsed Great Northern beans, and the can of diced green chiles (with their liquid). Reduce heat to low and let the mixture simmer for 10-15 minutes, stirring occasionally, to allow the flavors to meld. The chili should be thick and creamy.

While the chili simmers, warm your tortillas. Spoon a generous amount of the white chicken chili filling into each warm tortilla. Garnish with your favorite toppings and serve immediately.