how to add recipes depending on the provider

[Liora Milbaum]

I have two providers: virtualbox and aws
The provisioner is: chef zero

How do I add different recipes according to the provider?

For example:

    clm.vm.provision :chef_zero do |chef|
        chef.cookbooks_path = ["./cookbooks/"]
        chef.environments_path = ["./environments/"]
        chef.environment = 'prev'
        chef.add_recipe "CLM::init"
        if provider == "aws"
          chef.add_recipe "base::ec2"
        end
    end