Fresh produce and alfalfa hay. You can order the hay from Amazon. No pellets.
This.
Our guinea pig won't eat the alfalfa pellets but is nibling on the alfalfa cubes (you need to check that they're 100% alfalfa because most are mixed with chometz).
Along with loads and loads of hay (fill up 2x a day).
And lots of fresh produce (and the water bottle of course).
