What do you do if you're prepping a meal and run out of a key ingredient? Get Sara Moulton's swaps for salad dressing and seasonings!

Vinaigrette salad dressing: If you run out of oil, there are several substitutions that will work for a salad dressing recipe. The basic ratio is 2 tablespoons of the "stretching" ingredients to 1 tablespoon vinegar, pinch of salt and a little mustard and 1 tablespoon oil for a yield of 1/4 cup dressing. Try one of the following substitutions:
• Chicken, veggie or beef broth: Whisk together 1 tablespoon vinegar, pinch salt, a little Dijon mustard, 2 tablespoons of broth until the salt is dissolved, and 1 tablespoon of oil. Or, if you prefer a Catalina or French dressing use 2 tablespoons of tomato juice instead of broth, skip the salt if the tomato juice is salted.

• Fresh tomato: Grate a tomato into a pulp to be used as the substitution by cutting a vine-ripened tomato in half horizontally, scooping out the seeds with a tiny spoon, and grating each tomato half on a four-sided grater. Place the cut side of the tomato flat against the coarse side of the grater. Discard the skin and combine 2 tablespoons of the pulp with 1 tablespoon vinegar, a pinch of salt and a little Dijon mustard. Whisk until the salt is dissolved, add 1 tablespoon oil.

Replace fresh herbs with dry herbs in a recipe: For every tablespoon of fresh herbs in a recipe use one teaspoon of a dried herb. "When you use dry," Sarah adds, "generally you add it at the beginning of the recipe so it can resuscitate and become alive again. The fresh [herbs] you add at the end."

Ketchup: If you run out of ketchup for your next burger recipe, you can whip up a replacement by combining 1 cup tomato sauce, 1 teaspoon of sugar (add more if desired) and 1 teaspoon cider vinegar.

Mustard: Dried mustard can be used as the base for a mustard if you run out of the condiment. Mix 1 tablespoon dried mustard, 1 teaspoon water, 1 teaspoon vinegar, along with a hefty pinch of salt as a substitute for the French/German style of mustard. Add honey for a honey-mustard flavor.