If you're just starting to make the transition to organic, the smartest plan of attack is to prioritize your grocery list—i.e. invest in a bottle of good olive oil before splurging on organic chocolate. Fallon recommends getting started with these staples (which, even if you can't find organic, are still a good way to start improving your diet):

Proteins: Eggs; chicken; luncheon meats

Fats: Butter; olive oil; coconut oil

Dairy: Cheese; full-fat plain yogurt; cream

Carbohydrates: Potatoes; oatmeal; brown rice; sourdough bread

Beverages: Sparkling water; freshly squeezed juices; herbal teas

Condiments: Sauerkraut; kim chee; mustard; ketchup