One of the more common extensions of the phrase "on toast", generally used in one of two ways:

Def. 1 (verb): To do something extremely adeptly or well.

Def. 2 (verb): To be exceptionally good or enjoyable.
Def. 1 - Of course Anna wasn't very good at archery the first time she picked up a bow this year, but after a couple months practice she really started to rock on toast during competitions.

Def. 2 - Plush new carpeting, utilities included, central location, and only $450 a month in rent?
Man, your new apartment rocks on toast!
by Peter K. November 28, 2006
Get the rock on toast mug.
>adj<
1. the event, situation, or performance is very good and very pleasing
2. an individual that is outstanding in some way, or has possibly taken action that is outstanding

“Rock” is referring to “that rocks!”, which means a good or pleasing event, situation, or performance. “Toast” refers to the result of defeating odds or accomplishing a goal, also sometimes as the intended, confident positive result of a goal. An example of this meaning is used in Ghostbusters, “This chick is toast!”, meaning “We will very successful in defeating this woman”, so much, in fact, her existence itself would be as dry and crumbly as toast. In combination, then, the ‘rock’ part is used as the praise and degree of the skill involved in the “toast”, the successful result of the endeavor.

"Finally got my high speed internet set up at the new place!"

"Rock Toast!"
by Violet Chaos November 2, 2008
Get the rock toast mug.