And keep in mind, that while I understand not wanting your child to have aversions, MOST pedi's advice around solids is given with the assumption that you will be DONE nursing by the year point. Even thought it goes AGAINST what they chant. Which is "Breast milk should be your child's MAIN source of nutrition for AT LEAST one year.
So that statement DOES NOT suggest that at the year point your child should be getting all their nutrition from solid food. It means the change should BEGIN at that point. All food at this point is for fun an exploration only. So that your child begin to get used to other tastes and textures and begins to learn how to chew ect. To me, mixing formula with cereal doesn't sound "Fun".
And remember your child won't even associate solid food with taste for MONTHS and won't associate it with hunger until AFTER the year point. TO her this is all just a new game. She still associates eating, with you.
I'd skip the cereal AND the formula.