This is a fantastic way to use up leftover Thanksgiving turkey! It’s also great with rotisserie chicken or other leftover chicken you might have on hand.
In a large nonstick skillet, heat oil over medium heat and add onion, cooking until the onion begins to soften (about 2 minutes), stirring occasionally.
Whisk flour into milk. Slowly add milk mixture and broth to pan, whisking continuously as you do so, until the mixture is smoothly combined. Increase heat to bring mixture to a boil.