It looks like a butterhead lettuce, to me! Taste it and see. :-) (and then save the seeds).

It isn't Chard. Nor does it look like a lettuce to me. Perhaps a Chicory.

It turns out that it does have a bit of stem buried deep inside. This is the first time I've tried to pick a leaf. I'm trying to determine if I want to keep it or pull it out for more gardening area. I nibbled some of the top of the leaf. It was kind of bitter, but to be honest, I don't know what chard is supposed to taste like. The plant has a smaller twin down the row.

Thanks!

@floral_uk Thanks for the input! I didn't know that Chicory came in broad-leaf varieties. The chicory I'm thinking of is a roadside weed that is prevalent in many places though I haven't seen it around here.

Hmm ... if it is chicory, does that mean I can use its roots as a coffee substitute?

"chicory" includes "radicchio", which are quite bitter when not grown well.

It would seem that radicchio does not lend itself to the coffee substitute.

Radicchio de Treviso? There are some green radicchios:

https://www.westcoastseeds.com/shop/vegetable-seeds/chicory-seeds/radicchio-seeds/treviso/

What you have is at a pretty mature stage of development, which can lead to bitterness in a lot of greens. But I agree that the stem doesn't look like lettuce. Definitely a salad green, though, rather than a chard, which isn't usually bitter, more salty. But the Italians cook a lot of their bitter greens to ease the bitterness. Often they do a quick blanch, and then throw in a pan with olive oil, garlic and lots of salt and pepper...

Yes, Chicory comes in various guises. Red radicchio is a popular winter one and very hardy.

So, it's probably Radicchio de Treviso though it isn't growing upright like an urn per the description, possibly due to over-wintering. My spouse likes dark and bitter greens, so maybe I'll stir fry some up and see what she thinks. Thanks everyone!