Heat olive oil in a medium pot over medium heat. Add onions, garlic, and peppers, cooking until onions are translucent (about 5 minutes).
Stir in tomatoes, bay leaf, salt, and pepper. Add chicken breast and cover with chicken stock. Bring to a boil, then simmer on low for 30 minutes, stirring occasionally.
Remove chicken, chop roughly, and set aside.
Blend the vegetable mixture until smooth using an immersion blender or regular blender. Return it to the pot.
Add chicken back to the pot and simmer on low for 45 minutes, until most of the liquid evaporates.
Shred the chicken with a fork and set aside.
Cook fries according to package directions until crispy.
For the cheese sauce, melt butter in a saucepan, whisk in flour, then milk, and cook on low until thickened. Stir in cheese, salt, pepper, and chili powder until smooth.
Assemble by placing fries on a plate, topping with chicken, cheese sauce, salsa, green onions, jalapenos, and avocado. Enjoy!