It's being called an "informal inquiry" into the company's past practices of granting stock options. The Calabasas Hills-based chain also disclosed the filing of two shareholders suits alleging a breach of fiduciary duty and unjust enrichment related to its option granting practices. A couple of weeks ago, the company said it was voluntarily reviewing its stock option granting practice and would delay filing full second quarter results until the review is completed. The review was prompted by reports concerning possible backdating of stock option grants by a number of companies.