Pre Tri Dinner

I would not do anything different than you already eat the night before a big training day. This isn't the point in time to try anything new.

In my experience of ONE race, I had giant raviolis and bread, no red sauce here either.  I felt great race day, although I am not accustomed to eating food like that at night.  I am certain it helped me feel good for the race, as in my training bricks I never felt that good nor did I ever eat like that.

From what I've read the idea of a big pasta dinner to carb load the night before is no longer the best thinking.  I'd eat a smaller but balanced meal with lean protein and some carbs.  Be careful with too many veggies as the fiber can cause issues for some people.  I'll actually eat more in the days earlier leading up to the race.