Teresa Giudice -- A Bad Egg Before Prison

Sweet freedom tastes just like a sad egg sandwich -- at least that's what "Real Housewives of New Jersey" star Teresa Giudice wants to remember it was like.

Teresa was snapped at 2 AM Monday, somberly chowing down her last meal as a free woman -- a hot egg sandwich at Elmer's Diner in Danbury, where she'll be spending the next 15 months.

We're told she spent most of her time at the table with her lawyer ... on her phone, saying goodbye to friends.

Pretty sure she perked up when she saw that prison commissary list.