In a market when many high-flying tech stocks have seen their valuations soar, it's worth taking a look outside of tech for less flashy investments that may be getting overlooked. One industry that hasn't seen the same love from investors that popular tech stocks have is grocery stores.Sure, grocers are up against some major challenges, namely a rapidly evolving retail landscape and the threat of Amazon's (NASDAQ: AMZN) aggressive foray into the grocery business with its acquisition of Whole Foods.