Add butter to a small pot over medium-low heat.

Once the butter has melted, add the flour and whisk continuously for 1 minute, until thickened.

Add chicken broth (or vegetable broth), garlic powder, and onion powder to the pot, whisking until fully incorporated.

Increase heat to medium-high and let it come to a boil, whisking occasionally.

Once boiling, remove from heat and let cool down for 5 minutes.

If adding cream cheese, add it now, and stir it in until it melts.

Add the sour cream after the sauce has sat for 5 minutes and stir until fully combined.

The sauce will be thick like pudding before it sets up. You can add more chicken broth at this stage if you’d like to thin it a bit; add a little bit and stir until the desired consistency is reached.

Taste and add salt or white pepper, if necessary.

Pour over enchiladas, pasta, and more!