Pastore was born in Alhambra, California on August 21, 1957. He was valedictorian of the 1975 class of Damien High School, and was picked up by the Cincinnati Reds in the second round of the amateur draft that same year. After spending 4 somewhat unremarkable years in the minors (Pastore's career minor league record is 34-41 with a 3.28 ERA), he eventually made his major league debut on April 4, 1979 at Riverfront Stadium. In that game Pastore pitched three scoreless innings in a loss to the Giants. By the end of the 1979 season Pastore was moved into the starting rotation. In fact, he started Game 2 of the NLCS against the Pirates. Pastore limited Pittsburgh to two runs over seven innings. The Pirates won in extras, and the Reds lost in a three-game sweep.
Pastore's best season came in 1980 with the Reds, as he posted a record of 13 - 7 with an ERA of 3.27 in 27 appearances. For the most part he was mediocre in 1981 and '82, and the rest of his career followed this downward trajectory. Pastore claims that his pitching abilities were never the same after Steve Sax of the Dodgers hit a line drive off his right elbow in June 1984. He was released in April 1986 and finished the season with the Minnesota Twins. He pitched four games with the Texas Rangers organization at Triple-A in 1987, but that was the end of the line for Pastore.
Shortly after he was released by the Rangers, Pastore set a new record at the The Big Texan Steak Ranch restaurant in Amarillo, Texas by eating a meal that included a 72-ounce ribeye steak, salad, baked potato, shrimp cocktail, and roll in 9 minutes, 30 seconds. That record stood until it was broken by Joey Chestnut on March 24, 2008, when he finished his same-sized steak meal in just over 8 minutes.
After his baseball career ended, Pastore began to develop his intellectual and spiritual side. He earned degrees in business, religion, ethics, political science and theology at several universities. He wrote a book, and was a radio host with KKLA, a Christian talk radio station, from 2004 until his death on December 17, 2012. Pastore had been in a coma for four weeks after sustaining injuries in a motorcycle accident.