Accidentally deleted relationship laravel

so I have a relationship between two models

class Projects extends Model implements Auditable
{
    use SoftDeletes;
    use \OwenIt\Auditing\Auditable;

    protected $fillable = [
        'name', 'active'
    ];

    public function boards(){
        return $this->belongsTo(Board::class);
    }
}

And

class Board extends Model
{
    protected $guarded = [];

    public function projects(){
        return $this->hasMany(Projects::class);
    }

}

I wanted to empty the Board from its Projects without deleting the relationship. I thought this code would do the trick:

$board->projects()->delete()

But I ended up deleting the relationship.

My question now is how do I restore the relationship and what would be the best way to empty the relationship without actually deleting it?

via Chebli Mohamed