That says "FROMAJE GAUN" (separated by a vertical line so we know they are separate words). He sounded out "fromage jaune" (yellow cheese) by himself and wrote it. Pretty close!
And VERY proud of himself!
(On a side note, I'm not really sure what type of cheese "yellow cheese" refers to... possibly cheddar... but I'm sure Frédéric, the grocery shopper, will figure it out.)