It is common to add the wrong amount of a certain ingredient to a recipe. Often the mistake occurs when the chef misreads a recipe or the cap of a container falls off in mid-dash. When you add too much pepper to a recipe -- overly peppery soup, for instance -- there are a few options available to salvage the meal.
If extra ingredients are available and time permits, dilute the recipe. Add double amounts of all ingredients except pepper or other strong spices. You will likely need to create the second dish separately to avoid over- or undercooking either of the dishes. Once both batches are completed, combine them and stir well to blend the flavours. The resulting dish will offer a diluted alternative to the first. In addition, you'll have plenty of leftovers.
Add a teaspoon of lemon juice or one section of a quartered fresh lemon. The fruit's acid will neutralise the effect of the pepper. It may be necessary to simultaneously add a teaspoon of sugar to counteract the lemon's sourness. Add small amounts of lemon and sugar, tasting and adding more as needed. Because tomato and lime are also acidic juices, they may be used instead of lemon in recipes where they serve as appropriate, complementary ingredients.
Adding cream, yoghurt buttermilk or half-and-half can reduce the heat caused by too much pepper in potato soup, leek soup and similar meals, but does not work in all dishes. Sour cream works in recipes with thicker consistencies, such as white sauces. Again, add a small spoonful at a time, tasting and adding more as needed. The dairy trick can be used by itself or along with the lemon juice and sugar method.
If you feel uncomfortable adding unnecessary ingredients or simply don't have them on hand, try straining the extra pepper. Carefully pour thin sauce or soup into a second pot through cheesecloth or a strainer. This should remove a considerable amount of pepper grounds. If the dish is still too spicy, you can modify it, according to taste.