Let me get my credentials out of the way: I have been a Filipino for 30 plus years. Long enough to have opinions about bagoong brands, strong feelings about the “correct” way to eat sinigang, and a stomach that has seen things. In that time, I have eaten my way through more carinderias, buffets, and white-tablecloth heritage dining rooms than I care to admit to my cardiologist. So when I tell you these are the best Filipino heritage restaurants in Metro Manila, understand that this list was not compiled by a food blogger parachuting in for a weekend — it was compiled by someone whose lola would disown her if…