I keep it pretty simple when I do 1 gallon batches.
I brew in a bag with a a 3 gallon pot and a 2 gallon pot
Kettle 1 - heat 1 gallon to mash temp, drop in bag of grain, maintain temp.
Toward end of mash, heat 1 gallon in kettle 2 to mash out temp
End of mash, pull bag from kettle 1, drop into...