Even though it was filmed back in October, ABC and Marvel aired "Celebrating Stan Lee" on Dec 20, 2019 at 8 pm eastern.
As host, Clark opened up the evening in celebration of Stan the Man. There was many guests in the evening like Paul Bettany (Vision), Tom Hiddleston (Loki) & the one and only Ming-Na Wen (Agent Melinda May).
Below is a video of Clark talking about Stan Lee and what he means to him.
Here is a Video of Clark Gregg talking about meeting Stan Lee as well as his cameo on Marvel's Agents of SHIELD.
Below is the full hour that aired on ABC.