So I found this camera in my pocket and it turns out it makes phone calls, too. Technology! I called the local Cheesecake Factory and the guy on the phone said:
Nothing fancy, they're roasted red peppers.
He sounded pretty agitated, it's 7PM here so I probably caught him in the middle of dinner service.
You can buy them canned or roast them yourself. Much of the taste may have come from the sauce, or perhaps some special prep when they are roasted.
That said as pointed out in comments I am also now convinced that they look a bit on the small side. Tomorrow, during off hours, I'll call them back for a confirmation with more detail. We may have to try a corporate phone call and a tweet, too.
PS I've actually had that same dish and I also enjoyed it.