2 pounds small to medium Red Bliss potatoes (about 12)
Kosher salt
1/3 cup crème fraîche or mayonnaise
2 tablespoons red wine vinegar
1 tablespoon light corn syrup or 2 teaspoons sugar
1 teaspoon Dijon mustard
1 teaspoon celery seeds
1 small garlic clove, minced
1/4 cup canola oil, plus more for brushing
Pinch of crushed red pepper
1 teaspoon finely chopped fresh oregano
1/2 cup chopped parsley plus 1 teaspoon minced parsley
Freshly ground pepper
1 English cucumber, thinly sliced
1/3 cup thinly sliced red onion