I have four lbs. of beef shoulder chunks that have been seared on one side then simmered for 3 hrs with aromatics. Suggestions for use?

If it's been braised for three hours it should already be stew. I was thinking chili myself but a long cooked piece of beef and chili are not necessarily good friends. Work it into an adobo made from rehydrated ancho or guaillo peppers and maybe your are onto something for a burrito or taco.

Shred for tacos, mix with sauce for baked ziti, BBQ beef sandwiches, beef barley soup, chop and make a version of shepard's pie.

Beef pot pie is one of my favorite. Or shred the beef and pan fry till crispy and use for carnitas.

Chili maybe or a stew