Two possible solutions I can think of but would req new pendant. One is to use one with a chain. The other is to install a light that is assymmetrical.

I like that last idea!

I was hoping anybody would know of a pendant housing that does this

Is the intent to provide light for just the countertop, or for the countertop plus the range side of the counter as well? If it's just for the counter, I'd have to imagine there are shade options that would direct the light to that area.

Or could you come out the side of the beam with the wiring? You might be able to use something like this with a short arm on it to pretty close to being centered over the peninsula.

Not sure why my pictures aren't posting - here's a link to an option with the short arm.

That's one of my favorite lights but I don't think it works there. I'd replace it with a Halo SMD 4" surface mount light whose "guts" can be pushed into the electrical box embedded in the beam...if it will fit and the light's diameter does not exceed the width of the beam.