Cinnamon adds sweetness and a slightly exotic touch to a stew, but go overboard in adding it and you'll discover just what "too much of a good thing" means. Depending on the type of cinnamon you add, you may find the stew is actually somewhat spicy as well as sweet. You don't have to throw it out and start all over, but there is no exact science for fixing overspiced dishes, so you might have to experiment to find the best remedy for balancing the flavor.
Add More Ingredients
The easiest way to balance an overspiced stew is to add more ingredients to the mix. If you made a stew with meat, such as beef or lamb, sear more meat in a skillet first before adding it to the stew. Go easy on adding extra meat to keep the fat content down. Extra vegetables, such as potatoes and carrots, also dilute the flavor of too much cinnamon and are a healthier addition than more meat. Saute vegetables before adding them to the stew and do not season them. You might find that adding tomatoes to a stew helps balance the flavor.
When cinnamon is too strong, you can add other spices to balance the flavor. Go carefully and add a little bit at a time, taste testing as you go, or you may completely overpower the dish. If the cinnamon flavor is too sweet, add a contrasting strong spice, such as chili powder, lemon pepper, garlic powder or paprika. If the cinnamon is on the spicy side, add white or brown sugar and a sweet spice, such as nutmeg. A little salt may also help, but use it sparingly, particularly if you're watching your sodium intake.
Adding extra liquid to your stew dilutes the flavor of too much cinnamon. Use a mild broth, such as vegetable stock, and add a cup at a time. The acidity of tomato juice can also help even out the flavor of your stew. A strongly spiced stew can be toned down with the addition of a dairy product, such as milk or cream. Add a little hot broth to your dairy addition before mixing it into the stew to prevent curdling, and use it in moderation because of the fat content. Some stews benefit from the addition of a sour liquid to balance sweetness. Use lemon juice or red wine vinegar in small amounts.
If the cinnamon flavor isn't too sweet, add honey a spoonful at a time until the dish is palatable. If you add more liquid to your stew and find that it becomes too thin, mix cornstarch in water and add it to the hot stew as a thickener. Sour cream can also act as a thickener, while also evening out a spicy tone. When balancing flavors, add a little bit of your corrective ingredient at a time and taste as you go.