The easiest way to copy Olive Garden's pasta e fagioli is to visit one of the many copycat recipe sites to find a recipe that has already been tested. Similar recipes are available on TopSecretRecipes.com, CDKitchen.com and Food.com.
Olive Garden names ground beef, white and red beans, tubetti pasta and tomatoes as the main ingredients in its pasta e fagioli, but the recipe on Todd Wilbur's Top Secret Recipes site actually uses 17 ingredients to make the dish, including a variety of vegetables and spices, vinegar and tomato sauce. The recipe is fairly simple, despite the large number of ingredients needed. Brown the ground beef and saute the vegetables first. Once those ingredients are ready, mix everything together except for the pasta, and let it simmer for an hour. Just before serving, cook the pasta until it is al dente, and then add it to the soup.
There are two main differences that are apparent between Todd Wilbur's recipe and the information on the Olive Garden site. Wilbur calls for ditali pasta, while Olive Garden claims to use tubetti pasta which is similar in shape to ditali but a bit longer. Serving sizes aren't listed on either site, but Olive Garden's pasta e fagioli has 180 calories per serving while the TopSecretRecipes.com recipe claims to have 400 calories per serving.