As I was reading the press release for Taco Bell's new protein-packed power platform, I couldn't help but think of Chipotle Mexican Grill (CMG 6.47%). All this Fool saw was the words burrito and bowl used over and over by Yum! Brands (YUM -0.18%) in the press release. It was a subtle reminder that Taco Bell still wants to take down Chipotle.

Yum! Brands and its beef with Chipotle
Taco Bell's Cantina Bell menu was supposed to be the nail in Chipotle's coffin. After all, if Taco Bell could replicate Chipotle's menu and do so at a lower price, why wouldn't consumers switch? The Cantina Bell menu added Cantina Bowls and Cantina Steak Burritos to Taco Bell's menu board.

Source: Taco Bell

This was what hedge fund manager David Einhorn was thinking when he bet against Chipotle's shares back in 2012. He was confident that the Cantina Bell menu would succeed against Chipotle. At the time, he said, "Taco Bell has started to eat Chipotle's lunch." Unfortunately for him and his investors, his bet on Chipotle shares falling ended up being a costly mistake.

Source: Chipotle Mexican Grill

The problem for Yum! Brands and Taco Bell is that Chipotle's customers just would not trade down to Taco Bell. Taco Bell remains a value proposition, which is why earlier this year Yum! Brands launched a new concept called U.S. Taco Co. and Urban Taproom. Executives at Yum! Brands are hoping that it could be their Chipotle killer.

Source: Yum! Brands

Unfortunately, Yum! Brands has hit a few snags with this new concept. For one, the first location will be more like U.S. Taco Co. without the taproom. Yum! Brands was unable to secure a liquor license for the first location in Huntington Beach, California. Now customers won't be able to try the "Mexican Car Bomb," which will feature vanilla ice cream, tequila caramel sauce, chocolate flakes, and Guinness Stout. Without the liquor license, executives at Yum! Brands had to go back to the drawing board and taste over 100 sodas to put on the menu instead. Originally, the plan was to have taco-beer pairings, now the Huntington Beach location will have taco-soda pairings.

Another bite at the apple
Taco Bell looks to be retooling the Cantina Bell menu with its new Power Platform. The new menu launches nationally this month. It'll feature the Cantina Power Menu with bowls and burritos under 500 calories packed with 29 grams of protein for the Burrito and 28 grams of protein in the Bowl. It's also an effort by Taco Bell to capture the latest diet craze, the Paleo or caveman diet. This diet focuses on only eating meats, vegetables, and fruits that were available in the Stone Age.

Source: Nation's Restaurant News

Taco Bell is also emphasizing that the ingredients on the Power Menu are all fresh to appeal to Chipotle customers. The pricing is certainly hard for Chipotle to beat. The Chicken Burrito is $3.79 and the Steak Burrito is $3.99. The Bowls cost a little more with the Chicken Bowl priced at $4.99 and the Steak Bowl at $5.19. There is also a vegetarian option without the meat that uses more beans instead which is priced at $3.79 for the Burrito and $4.99 for the Bowl.

One area where Taco Bell is beating Chipotle
The one area where Taco Bell has Chipotle beat is breakfast--but that's only because Chipotle doesn't serve breakfast. Taco Bell has been looking to steal McDonald's share of the breakfast market with its new breakfast menu, and it plans to take the battle with McDonald's a step further next month with its Power Breakfast Menu. Taco Bell will be testing the Power Breakfast Menu in Omaha, Nebraska, a menu that features Power Greek Yogurt with 17 grams of protein and 240 calories for $2.49. It also has the Power Breakfast Steak Bowl and Burrito priced at $2.79 each.

Earnings report showed Taco Bell making progress
Taco Bell's same-store sales grew 2% in the second quarter. It looks like the new breakfast menu is working since same-store sales were a negative 1% in the first quarter. Breakfast accounted for about 7% of sales in the second quarter. Taco Bell expects annual sales to be $70,000 to $120,000 per unit. This is still a far cry from the average McDonald's, which gets about $1 million in sales just from breakfast.

A closer look at the shares of each company
In terms of sales growth, there is no comparison to Chipotle--it wins hands down. Its 13% same-store sales increase in the most recent quarter surprised even the chain's biggest skeptics. But with shares trading at 36 times next year's earnings, it'll have to maintain that growth to keep the shares on their path higher. Shares of Yum! Brands, on the other hand, aren't looking too bad. They're trading at just 18 times next year's earnings. That said, Yum! Brands beats Chipotle in terms of return on equity. Yum! Brands 47% return on equity is more than double Chipotle's 22% return on equity.

Foolish final thoughts
If Yum! Brands wants to take down Chipotle, it'll most likely have to do it with Taco Bell. Only Taco Bell has the scale to ramp up the sales growth a company like Yum! Brands needs. Building a new concept from scratch takes too much time and money. For shareholders, time is not something they want to hear. They want to see results and top-and bottom-line growth. By continuing to tweak Taco Bell, Yum! Brands is hoping to deliver the growth its shareholders are looking for. Adding more protein to Taco Bell's menu is certainly a step in the right direction for Yum! Brands.