Preheat the oven to 400ºF.
Toss the cut potatoes with olive oil, salt, and pepper and arrange them into a single layer on a large baking sheet. Cut 1/4 to 1/2-inch off the top of the garlic head, exposing the bulbs. Drizzle a little olive oil over the top and add a pinch of salt. Wrap tightly with foil to keep the steam in and place on the baking sheet with the potatoes. Roast for 25 minutes, flip the potatoes and cook for another 15 minutes.
Remove the garlic from the sheet pan and carefully open up the foil to let the steam out. Set it aside to cool for a few minutes.
Toss the asparagus spears with 1/2 teaspoon of kosher salt and 1/4 teaspoon of black pepper. Carefully place them amongst the potatoes and cook for an additional 5-7 minutes until lightly warmed through but still bright green, crunchy, and al dente in texture.
Make the roasted garlic vinaigrette. Squeeze out the garlic cloves into a blender along with the extra virgin olive oil, red wine vinegar, dijon mustard, honey, salt, and pepper. Blend until smooth, adjusting the salt and pepper, to taste as needed.
Add the roasted potatoes and asparagus to a large serving bowl. Pour the dressing over the top and toss until the vegetables are evenly coated. Garnish with fresh chopped parsley and serve warm or at room temperature.