I got this recipe from a coworker about a year ago. I made a few adaptations but it is the only dressing I eat now. Super easy and delicious. I always have these ingredients on hand too which makes it convenient.
-1 part Balsamic vinegar (1/4 cup) to 2 parts oil (1/2 cup)
-1-2 T of honey
-1 T of Dijon mustard (double check ingredients list for MSPI safe brands. I use Trader Joe's)
-1 tsp of garlic salt
-pepper to taste
Mix everything together except the oil.
Gradually add oil by whisking.
The Dijon mustard is the key to emulsification, if the oil and the other parts are not combining well, add more mustard, but be careful because it can definitely take over in taste.