I always keep my eyes open for investment opportunities. The best method is to literally keep them open when you are out and about doing your daily business. This is one of the ways I’ve found multi-bagger stocks over the years.

Everyday items can certainly provide investors with good returns, but these companies tend to be what Peter Lynch called “stalwarts” — slow growing companies paying a nice dividend that should form the cornerstone of your portfolio.

However, it is the companies behind the scenes or right under your nose that provide the big growth opportunities. Many years ago, I invested in a company called Flextronics (Nasdaq: FLEX). At the time, the company was providing a lot of the parts and electronics that went inside things like cellular phones.

While I was in a Subway sandwich store a few weeks ago, I saw the employees rapidly heat up the sandwiches in a TurboChef oven. I thought a super-fast oven was a neat idea, but also dismayed to learn the company had been purchased in 2008 by Middleby Corporation (Nasdaq: MIDD), a company that designs, manufactures and sells commercial foodservice and food processing equipment.

That’s when it hit me that ovens must be big business. Every single restaurant at home and abroad uses ovens, not to mention any number of institutions like hospitals and businesses. I wasn’t the first to discover the company. The stock has returned about +500% since 2003, and you could’ve had it during the market bottom of 2009 for about -67% off the current price.

#-ad_banner-#I still like what I see in Middleby, though, and think it has room to grow. This means more than ovens. It means toasters, griddles, charbroilers — lots of hot appliances. And as it turns out, hot is better than cold. Cold appliances like refrigerators are commodities at this point — cooling something doesn’t take much imagination or effort, from a design perspective. Hot appliances are far more complicated in design and require more study before purchasing. Heating something also entails several different methods — baking, frying, broiling, etc. That means lots of different products to create and sell.

Middleby’s business is truly global, serving dozens of countries across the globe. Ovens are like Coca-Cola (NYSE: KO) — there’s no reason why every place that can sell the product shouldn’t sell the product. It means infinite expansion possibility.

Another secret to Middleby’s success is the same reason why businesses like car dealership maintenance centers are so profitable — service contracts. It isn’t enough to just buy a Middleby product, a client will want to purchase a service contract. Appliances will need service no matter how well-made they are. It’s a bit like purchasing insurance. It costs Middleby less to come out and service a unit annually than what it collects to contract the service. This also means recurring revenue.

There’s also a secular trend here in the United States, one that will unquestionably resume when the recession ends, and that is that Americans love to eat out. According to some estimates, we spend almost half of our food money eating outside the home.

Financially, Middleby is on solid ground. The company experienced a +9.3% sales increase in the second quarter, and a +12% rise in earnings. Free cash flow has been increasing over the years — from $56 million in 2007 to $95 million in 2009.

Action to Take –> Buy Middleby. Analyst’s foresee +20% compound annual earnings growth during the next five years. If the stock price follows suit, as one would expect, that would suggest a +150% return. Backing off to a more conservative view of +15% earnings growth, you’re looking at a solid double for a company with an entire planet to conquer and the resources to make it happen.