I spent $5,000 to start a business in my kitchen—now it brings in $147 million a year

When Elizabeth Stein started her natural food company Purely Elizabeth in 2009, she sold muffin and pancake mixes made with ancient grains. It wasn't until 2011, after she made a batch of homemade granola for her mom, that her company really took off. The company that began in Stein's kitchen now brings in $147 million per year in sales, according to documents reviewed by CNBC Make It.