Is there any alcohol remaining in beer-stewed chicken?
The short answer is:  it depends, on exactly how you cooked the dish, and what other ingredients are in it.

In practice, for a long simmered dish, the answer is going to approach about 20% as documented in the USDA Table of Nutrient Retention Factors Release 6 under the table entry "ALC BEV,STIRRED,BKD/SIMMRD 1.5 HR".  Increasing time to 2.5 hours would go down to about 5%.