Preheat the oven to 400 degrees F.

In a mixing bowl, toss the potatoes and garlic with a drizzle of olive oil. Toss well. Season with salt and pepper. Place on a baking sheet and roast for 20 minutes, or until fork tender. Remove from the oven and cool completely. Using ai food processor, combine the mayonnaise, mustard and lemon juice. Process until smooth. Season with salt and pepper. Add the cilantro and continue to process until incorporated. In a mixing bowl, toss the roasted potatoes and garlic, cilantro mayonnaise, sliced eggs, and red onions. Mix well. Season with salt and pepper. Serve immediately or cover with plastic wrap and refrigerate for 2 hours. Remove from the refrigerator and mix the salad. Reseason with salt and pepper if needed.