The recipe came out great! It was like tasting tomato sauce for the first time. We ate it with bread, with pasta, and finally just by itself like soup. I used the Pomi brand tomatoes, but I will try the recipe with Cento brand San Marzano tomatoes to make sure it wasn’t the method. (I never grated onions for a tomato sauce before.)
To be honest, I buy the San Marzanos because of what experts say. A few other canned tomatos – from Cento and others – taste better to me in tomato sauce. I like the San Marzanos in salsa, though.
As for passata being cooked vs uncooked, I have a theory. I think the manufacturers are able to get a thick consistency without cooking, but, at home, cooking is necessary to get rid of excess moisture. I wonder if you could just strain over double cheesecloth.
I found another brand of passata near me. This one was jarred and the word “passata” is actually printed on the label. I haven’t cooked with it, but raw, I thought the jarred one tasted better than the Pomi. I attached some pictures below.