from typing import List


def get_common_keys(first: List[str], second: List[str]) -> List[str]:
    """Get common elements of two sets of strings in a case insensitive way.

    Args:
        first (List[str]): First list of strings.
        second (List[str]): List of strings to search for matches.

    Returns:
        List[str]: List of common elements without regarding case of first list.
    """
    return [value for value in first if value in second or value.lower() in second]