As much as I love tomato sauce, (sorry everyone!) DH takes it a bit far by commiting my ultimate croime against food:

Tomato sauce on corned silverside.

Others that make me go eeeeeew:

-- "Risotto" made with basmati or jasmine rice
-- fake cream in cream cakes (This would be number on if it were DH's list)
-- using round hundreds and thousands in fairy bread instead of flat sprinkles
-- "guacamole" that is little more than over salted, pureed avocado
-- Ryans Family Restaurant in Warrnambool