French's use to make a mustard with tiny sweet onions in it and I loved it. They no longer make it so I found this recipe and it is kind of like that mustard. Really good on sandwiches and especially good on hot dogs. Can be canned for gifts also
Combine mustard seeds, dry mustard and warm water. Let sit for 4 hours.
Combine vinegar, onions, garlic brown sugar and salt and cook over med heat for 15 minutes. Remove from heat. Stir in seed mixture. Blend until smooth with an immersion blender or food processor or blender.