Pershing Square Capital’s Bill Ackman still has high hopes that Chipotle will rebound and become a big winner for his hedge-fund.

“We’re going to work hard to help the company turn,” Ackman said on CNBC’s “Halftime Report” Monday. “This is an eminently fixable company … This is still a great concept.”

The hedge fund manager said Chipotle can improve its financial results by adding drive-throughs, longer hours and a breakfast offering and by expanding overseas. The burrito chain restaurant has struggled to win back customers after a series of food safety issues.

“We’re not just betting on a recovery from the food safety issue,” Ackman said on CNBC. “This is one of the least optimized of the quick service restaurants.”

The investor also shared how he is valuing the restaurant chain.

“The right way to look at it in our view is not just to put a multiple on next year’s” earnings, he said. Instead he looks at “what’s a reasonable trajectory for a recovery and what will the earnings be two years out? Four years out? … And then discount those earnings back in time. On that basis it’s a very cheap stock if they can perform.”

Chipotle dropped 15 percent on Oct. 25, a day after the company reported disappointing third-quarter results. Its shares are down 27.5 percent year to date through Friday compared to the S&P 500’s 15.6 percent gain.

Pershing Square is the largest shareholder of Chipotle. The firm owned 2.9 million shares, or 10.2 percent of the company, as of the end of June, according to FactSet.

Ackman has stumbled in recent years with high-profile losing bets like Valeant Pharmaceuticals.

Pershing Square Holdings has been underperforming the stock market this year. The fund is down 3.3 percent year-to-date return through Oct. 31, according to its website.