I have a recipe that I got from the Herb Companion magazine. It does contain dijon mustard (which would have a different flavor that reg. mustard), but I never noticed that it was too mustardy and I always get requests for the recipe. You could try making it without the mustard or even reducing the amount if you really don't like it that way.
12 oz. raspberries
1c. red wine vinegar
2 T. dijon mustard
1 tsp. salt
2 - 3 T. fresh minced cilantro, thyme, mint, basil or arugula
2 1/2 c. olive oil
Whisk the raspberries, vinegar, mustard, seasoning and herbs in bowl. Slowly drizzle in the oil while continuing to whisk. Use immediately or refrigerate. If kept refrigerated, the vinaigrette should keep for up to 2 weeks. Shake well befor serving.
I usually make this with the basil and thyme. I also just put tit all in a shaker to mix it.