In the first half of this strip, the guy realizes that he has extra cheese in his refrigerator, and that if he went to buy some chips he could make some nachos. In the second half, which takes place some time after the first, he realizes that he has extra chips, and that if he went to buy some cheese he could make some nachos. He apparently doesn’t think back to the inverted situation that occurred in the first half, which is the source of said “extra” chips. It’s a whimsical observation of how the two ingredients are mismatched in quantity relative to the amounts needed in preparation of the dish, and how from then on there will always be one ingredient left over, thus perpetuating the cycle.
A similar, yet not perfectly analogous, situation would be a pack of hot dogs containing 6 franks, and a bag of 8 hot dog buns. After you prepare and eat all 6 franks, there will be 2 buns left over, which would then prompt you to go buy more franks to use with the extra buns. You’d of course then have 4 franks left over, so you’d need to buy another pack of 8 buns, et cetera, et cetera…
In what seems to be a recurring theme throughout the strip, the author once again reinforces the stereotype that, to the target audience, nachos are the perfect delicacy.