Preheat your oven to 400°F (200°C).

On a large baking sheet, arrange the trimmed asparagus and halved radishes. Drizzle with olive oil, and generously season with salt and pepper. Toss the vegetables until well-coated.

Roast for 20 to 25 minutes, turning halfway through. The radishes should be lightly browned and tender; asparagus should be vibrant and slightly crisp.

While roasting, whisk together the whole grain mustard, Dijon mustard, red wine vinegar, minced garlic, and olive oil until emulsified and creamy.

Taste and adjust vinaigrette with salt, pepper, and optional honey or maple syrup.

Once cooked, let the vegetables cool slightly and arrange them on a serving platter.

Drizzle the mustard vinaigrette over the roasted vegetables and serve warm, at room temperature, or chilled.