Salad Bars in Schools Expansion Act This bill requires the Department of Agriculture (USDA) to establish and implement a plan, including through a five-year program of competitive grants, to promote the use of salad bars in schools participating in the school lunch program. Priority in the award of grants may be given to entities that (1) serve schools in which at least 50% of the students are eligible for free or reduced-price lunches or that are located in food deserts, or (2) provide nutrition education. Food desert is defined as a census tract with a substantial share of residents who live in low-income areas that have low levels of access to a grocery store or a healthy, affordable food retail outlet. USDA must also (1) submit a report to Congress that includes recommendations for promoting and establishing more salad bars in schools; and (2) revise the March 27, 2013, policy memorandum SP 31-2013, Salad Bars in the National School Lunch Program, in light of the recommendations.