After a year of nursing school she fell in love with her childhood friend Otto W. Siebert, heir to the Siebert Baby Carriage Co. of Gardner, Massachusetts, the largest manufacturer of baby and doll carriages.  Marriage soon followed and Phyllis assumed her new role as hostess for the Siebert Company in Gardner and later in their apartment in New York City.  This was the beginning of her sojourn into the world of culinary magic.

Her early teacher was her mother-in-law's household chef who had come to the family's kitchen following employment with Gloria Swanson and Morton Downey.  Phyllis was soon serving her guests the same gastronomic delights that her teacher had prepared for Howard Hughes, Orson Wells, Greta Garbo and William Randolph Hearst when they had dined at Swanson's table.

Following the sale of the Siebert Company, the Sieberts divided their time between their homes in new York City and Westport Island, Maine, where they had first met in the summer of 1945.  In the early 60's they moved to Maine permanently and Otto went to work for the State of maine Finance and Administration, Deputy Commissioner of Finance and Administration, State Budget Officer and Financial Manager of the maine Attorney General's Office.

The transition for  business hostess to political hostess was an easy one for Phyllis.  Over the years her interest in great food had become a passion and she was learning all the time from all the great cooks she encountered.  In the mid 50's her mother-in-law purchased and restored what is now known as The Squire Tarbox Inn on Westport Island.  In the early 60's the elder Mrs. Siebert, widowed, married Alfred L. Smith and set off on  a tour of the world, leaving the younger Sieberts living in the Inn.  Phyllis started the first gourmet bread company in the area.  She was soon turning 1000 pounds of flour into bread every week.  Then one day the phone rang and Olive Ross, executive assistant to Maine's First Lady Polly Curtis, was calling to ask if Phyllis would be interested in coming to work at the Blaine House as the governor's chef.  The answer was yes.  Except for a three year break in service when she went back to The Squire Tarbox Inn as its' chef from '76-'78, twenty-three years and five governors later she is still the most celebrated chef in Maine.