Your company should give you a procedure for that, as it is not covered in the Airbus SOPs.
When the engine failure occurs after acceleration but before the airplane is clean, you should go TOGA again (SRS will activate and also GA TRK) and you should pull speed and go back to V2 plus until reaching 1,700 ft in your example, then you can resume normal acceleration.
However! If you didn't, most likely the outcome is going to be the same and the take off safe, because you already climbed 1,200 ft on two engines, so you are quite good if you compare with a failure at V1.