What is the best way to implement "GetAll, GetBy" methods in repository pattern with Entity Framework Core?

I implement a repository pattern in my pet-project and I have a little question about realization of methods which return collections of items (for example: GetAll, GetBy). In current implementation the code of that methods look like below:

public IEnumerable<T> GetAll()
{
    return _context.Set<T>().ToList();
}

public IEnumerable<T> GetBy(Expression<Func<T, bool>> predicate)
{
    return
        predicate == null ?
            throw new ArgumentNullException(nameof(predicate)) :
            _context.Set<T>().Where(predicate).ToList;
}
public async Task<IEnumerable<T>> GetAllAsync()
{
    return await _context.Set<T>().ToListAsync();
}

public async Task<IEnumerable<T>> GetByAsync(Expression<Func<T, bool>> predicate)
{
    return
        predicate == null ?
        throw new ArgumentNullException(nameof(predicate)) :
        await _context.Set<T>().Where(predicate).ToListAsync();
}

I think that casting to list is not a good idea, so I tried to rewrite my code with using "yield return" and Enumerable, like below:

public IEnumerable<T> GetAll()
{
    foreach (var item in _context.Set<T>().AsEnumerable())
    {
        yield return item;
    }
}

But I have not found sample how to implement async version of this code. Could you give me some advice about best implementation of this stuff?