plant ID please. Lettuce?

I was wondering if you would be able to help me identifying this plant. We bought a farm in Alberta (zone 3) and this is popping up in the garden. It looks like some type of lettuce that reseeded itself but I want to make sure before we eat any. Thank you!

Maybe osaka purple mustard? Posibly from a mesculan mix?

It looks like deer tongue lettuce to me, the "Really Red" variety. But I don't know if it's fuzzy along the leaf veins like yours.

Libbie. That looks very much like it. Thanks!

Or if not some variety of lettuce, a chicory.

Hester Winterbourne wrote:Or if not some variety of lettuce, a chicory.

Very possible. It looked like a radicchio at first. Previous owners were Italian. Apart from tasting it, any other way to figure out what it is?

Wait 'til it flowers, by which time it will be too late!  If it is growing in the veg garden, chances are it is a some sort of veg.  Have a look around nearby wild areas and see if it is growing anywhere else.  Consider what your local toxic weeds are that it could be, I can't think of any likely culprits if it was growing on mine, except wild lettuce.