Choice parameter in a Jenkinsfile dynamically evaluated

I'm trying to add a dynamic choice parameter to a Jenkinsfile with declarative syntax, using something like this:

def myChoices = listBranchesFromGithub(MY_REPO)

pipeline {
    parameters {
        choice(name: 'mychoice', choices: myChoices)
    }
}

but listBranchesFromGithub(MY_REPO) is evaluated once (when the Jenkinsfile is processed), not everytime I run the job.

Is there a way to populate choices everytime the job is triggered?