Janet Sawyer-Gerber, founder and president of La Casita Mexican Grill, opened the original La Casita Patio Café on South Nevada Avenue on May 5, 1986 — inside a converted gas station. Forty years later, that modest beginning has grown into a Colorado Springs institution. At the time, it was simply a small eatery with a big idea. Few would have predicted it would endure relocations, economic downturns and even a global pandemic. The principles that guided Sawyer-Gerber then still anchor the business today: serve fresh food, treat people well and stay true to who you are. Now, four decades on, Sawyer-Gerber and Walter Gerber, who stepped into the restaurant’s operations after their marriage, are planning a four-day Cinco de Mayo celebration to mark the milestone. A familiar figure to longtime customers, Walter has become both operator and ambassador, greeting guests by name and helping carry forward the spirit that has sustained La Casita for 40 years. A stroll down memory lane The early days were humble.…