Is it OK to take a single 15A line off a 20A branch circuit. Specifically, I have a new 20A kitchen wall circuit which will exist only of two 20A counter GFCI outlets. I have had to rework that wall for the gas stove and want to run a 15A outlet for the gas stove electrics. Can I just take a 15A line out of the 20A junction in the cellar or does it need to also be 20A even though it's only for the stove electronics? Also, everything is within 8' - 10' of each other. Small kitchen.

Thanks

You can use a 15 amp receptacle -- but you must run 12 gage wire- Savage
Please note that I am not a electrician.

Savage is absolutely correct. Only thing I will add is that this outlet for the range does not need to be GFI protected, as the counter outlets do need to be. It can be if this is easier or desired.