I keep coming across recipes including this as an ingredient but i cannot find I anywhere. Could someone help me out with this recipe? I've been making everything without this part.

Greatly appreciated!!

2 tablespoons red wine vinegar
1 tablespoon finely chopped shallot
1 1/2 teaspoons dijon mustard
2 tablespoon extra virgin olive oil
1/8 teaspoon kosher salt
1/8 teaspoon freshly ground pepper
Combine vinegar and shallot. Let stand 5 min. Whisk in mustard. Add oil in a thin steady stream whisking constantly. Add salt&pepper. Lasts up to 3 days.
Nutrition per table spoon 51cal, 5g fat(1 g saturated fat) 85 mg sodium 1 g carb