Chipotle (NYSE:CMG) will post first-quarter earnings results after the market closes on April 21. And while it's had a huge run in the past few years, the stock hasn't yet recovered from the hammering it took back in February. 

CMG Chart

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The hit came after Chipotle booked fourth-quarter results that included a 16% spike in comparable-store sales and 52% higher profits. But investors sold the stock anyway on worries about higher food costs and a coming sales growth slowdown.

Here's a look at what to expect from the casual dining giant when it posts results on April 21.

Metric 2014 Q1 2015 Q1 (change)
Revenue $904 million $1.1 billion (22%)
Profit $2.64 per share $3.63 per share (38%)

2015 Q1 is Wall Street's projection. Source: Yahoo! Finance and company financial filings

Spicy sales growth
Wall Street analysts see Chipotle notching a 22% quarterly sales jump to $1.1 billion. Part of that boost will come from new locations. The company had 1,637 restaurants in its store base a year ago, but the figure should be closer to 1,800 now. Chipotle expects to open around 200 new restaurants this year, for roughly the same pace it kept in 2014.

However, the more important number to watch is comps, or sales growth at existing locations. Chipotle booked a 13% improvement on that metric a year ago, making it harder to engineer big gains this time. In fact, management is calling for "low to mid-single digit" comps for 2015 as a whole. That would mark a huge slowdown from the 17% it managed last year. But keep in mind that Chipotle offered the exact same sales growth guidance at the beginning of 2014 -- before blowing right past it.

Surging profits and costs
Chipotle should book $3.63 per share in first-quarter earnings, according to analysts. That would correspond to a 38% gain over the prior year. The fact that profits are rising faster than revenue is good news for investors. And it's even better news when you consider that Chipotle is managing the gains while food costs rise and menu prices stay put. In other words, it's earning those higher profits the hard way: by attracting more customer traffic and processing it at record-high speeds.

Source: The Motley Fool

Rising food expenses are still worth watching, even if overall profit growth is strong. Food costs hit a record-high 35% of sales last quarter and should be close to the same mark this quarter thanks to spiking ingredient costs.

Don't obsess over food costs, though. As Chipotle CFO John R. Hartung recently explained to investors, the company is being managed to maximize long-term total return as opposed to individual expenses like that: 

We just don't put a very high importance on our food cost as a percent of sales. What we've always focused more on is what is our overall margin and when we apply that margin to our sales, what is our unit economic return. At these sales and these margins and with the investment that we've got we're talking about a 70% or so return on investment which is roughly double what other successful chains are delivering.

Foolish wrap
Chipotle just finished its best year yet as a public company. Sales are up to a $4 billion annual pace as compared to the $700 million it averaged in 2006. Revenue at an average restaurant is now $2.5 million, up from $1.4 million a decade ago.

That quick improvement will make 2015 difficult in terms of the comps numbers that Chipotle is matched up against. But it also demonstrates that it is on to something big, both in its "food with integrity" mission and with its powerful economic model.