from typing import Counter


def most_common_elems(lst):
    """Returns the most common elements from a list.
    >>> most_common_elems([2, 2, 1])
    [2]
    >>> sorted(most_common_elems([2, 1]))
    [1, 2]
    >>> sorted(most_common_elems([3, 2, 1, 3, 2, 4, 5, 7, 3, 1, 1]))
    [1, 3]
    """
    c = Counter()
    for elem in lst:
        c[elem] += 1
    mc = c.most_common()
    return [elems for elems, count in mc if count == mc[0][1]]