Definition of have someone on toast in English:

have someone on toast

phrase

British
informal
  • Be in a position to deal with someone as one wishes.

    ‘the more he thought, the more I knew I had him on toast’
    • ‘The Packers, including Kerry, had him on toast.’
    • ‘Glenn McGrath had him on toast for the first two tests of the series before he reverted to No 4 for the final test and scored 65.’
    • ‘The leader of our northern neighbor has him on toast.’
    • ‘If I didn't turn up he would have had you on toast by now!’