Italian dressing is a great marinade for chicken and vegetables, but when you don't have any on hand, it is possible to substitute it in recipes without losing the flavor. The most important factors when choosing a substitute are the herbs and the oil.
Replacing a Dry Mix
It is simple and cost effective to make a replacement for dry mix Italian dressing. Mix together 1 1/2 tsp. garlic powder, 1 tbsp. onion powder, 2 tbsp. oregano, 1 tbsp. dried parsley, 1 tbsp. white sugar, 2 tbsp. salt, 1 tsp. black pepper, 1 tsp. basil, 1/4 tsp. thyme, and 1/2 tsp. dried celery flakes. Store this mixture in an airtight container and use as needed.
Make Your Own Dressing
Make your own dressing with what you already have in your pantry. Combine 1/4 cup white vinegar, 2/3 cup canola or olive oil and 2 tbsp. of water with 2 tbsp. of the dry mix.
Replace with Another Dressing
When replacing wet Italian dressing, anything that has the same oil-based moisture content will substitute nicely. Olive oil flavored with basil will work in a pinch. Oil-based vinaigrette works very well when replacing in a marinade. For dry mix substitutions, a different dry dressing like a ranch packet will add a distinctive flavor to the dish, but usually can be used interchangeably.