Food:
* Flour
* Sugar
* Rice
* Milk
* Water
* Oil
* Cheese
* Bread
* Meat
* Pasta
* Sauce
* Salt
* Pepper
* Chocolate
Ingredients and Supplies:
* Butter
* Cream
* Honey
* Syrup
* Jam
* Fruit (as a general category)
* Vegetables (as a general category)
* Coffee
* Tea
* Spices
* Herbs
* Vinegar
Other:
* Trash
* Garbage
* Dish soap
* Cleaning supplies
* Air
* Smoke
* Heat
Remember: Mass nouns are things that cannot be counted individually (e.g., you don't say "one flour"). We can only use them in singular form and usually talk about quantities of them.
Let me know if you'd like more examples!