I'm not sure there's a better approach for an incumbent administration. The alternative would have been, "Inflation is bad, but we're going to fix it if you elect us," which to the average voter raises the question: "Why not just fix it now?"
One option would be to reply with "out plans are measured in centuries, keep electing us and things will get better, eventually". But this would probably require to have such plans.
Trump stated his plan to lower food cost was to lower the cost of the energy inputs that he says are driving up the food costs; lower diesel cost for farmers and transportation and lower energy cost for fertilizer production.
If this will work or not, no idea. But it did play as a better soundbite than "I will hold the grocery stores who are price gouging you accountable for it" because that soundbite says "We have been letting them get away with charging you for 3 years and now that we have an election to win we promise to do something about it".
This gets close to the heart of why many seemingly reasonable people support Trump. He gives specifics. The specifics may be of a hare-brained scheme that can’t possibly work, but no other politician even goes that far.
1. Biden is good and inflation wasn't his fault
2. Biden's handling of it was good, he did all good things, Biden is good
3. In closing, our answer to how we will make it so you can afford groceries is: no