A writer I know recently twittered that she’d tried to make a big batch potato-leek soup, that it had turned out way to peppery even though she’d followed the recipe, and what could she do?
Fixing recipes is always interesting.
First, you can start over. This costs you style points — it’s literally unprofessional. But we’re not professional cooks, we’re just making dinner. Sometimes, you chalk it up to experience.
One of the best parts of Alice Water’s Simple Cooking is a list of pantry dinners — good dinners you can improvise from staples you’ve got lying around. The unsalvageable goof is the perfect time to hit the pantry. Spaghetti Alfredo, or a nice carbonara with whatever greens come to hand, or a gratin of potatoes and whatever else you've got handy will cover a host of ills.
Second, you can often double down, diluting your mistake by mixing it with another batch. A little too much salt in the soup? Make another batch of soup, don't salt it at all, and then add the salty soup gradually until it’s just right. (This won’t work very well, however, if you’ve added the wrong thing entirely. If you meant to reach for the apple cider and got cider vinegar instead and it tastes terrible, diluting it will just give you soup that tastes kinda terrible. Same for burnt: you can take things surprisingly far once you learn about deglazing the pan, but if it tastes like charcoal, you’re doomed.)
Third, treat the mistake as a product and use the flaw as a strength. Your soup has lots of nice leeks and potatoes and cream, but way too much pepper? There’s a whole family of recipes for things like “chicken casserole” which call for a can of cream soup. (Classically, they call for chicken velouté or béchamel, but your mom used Campbell’s Cream Of Mushroom. Listen to Mom. After all, who added all that pepper?) You make the same thing, but instead of canned soup you’re going to use a wonderful home-made stock that just happens to have been pre-seasoned. You’d be adding a lot of salt and pepper anyway; just add less pepper.