Is there a source for the idea of specially having a bread meal on Rosh Chodesh so that one can say the special insertion for Rosh Chodesh in the grace after meals?
related: Rosh Chodesh at home
Mishna Brurah commentary on O.C. 419:1 says that it is meritorious if one increases his feasting on Rosh Hodesh, however, it does not require eating foods that require Birkat Hamazon (i.e. bread), just an increase in the number of meals eaten as compared to a regular day, or an increase in the quantity.