Heat oil in a large pan over medium heat. Add flour and whisk together, cooking until starting to brown. Add chili powder and whisk together with flour and oil mixture. The mixture will be thick and dry.
Add water and chicken stock and whisk well until lumps are dissolved. Add in garlic powder and salt, and whisk until combined. Simmer over medium heat for approximately 10-15 minutes, until sauce begins to thicken, and sauce will coat/stick to a spoon when pulled out of sauce. Serve or store in an airtight container.
All chicken stock/broth or all water can be used for this recipe, though each will change the flavor a bit.