1) Add some sugar. Sugar can help to neutralize the bitterness of burnt food. Start by adding a small amount of sugar (about 1/2 teaspoon) and then taste the salsa. Continue to add sugar, a little bit at a time, until the burnt taste has disappeared.
2) Add some acid. Acid can also help to neutralize the bitterness of burnt food. You can add some vinegar, lemon juice, or lime juice to your salsa. Start by adding a small amount (about 1/4 cup) and then taste the salsa. Continue to add acid, a little bit at a time, until the burnt taste has disappeared.
3) Cook the salsa for a longer period of time. If the burnt taste is still there after you have added sugar and acid, you can try cooking the salsa for a longer period of time. This will help to mellow the flavors and remove the burnt taste.
4) Make a new batch of salsa. If you are unable to remove the burnt taste from your salsa, you may need to make a new batch. Be sure to follow the recipe carefully and avoid burning the salsa.