Preheat oven to 425 degrees.
Prepare vegetables: peel and slice carrots, slice and deseed acorn and delicata squash; arrange pieces on a rimmed baking sheet.
In a small bowl, whisk together coarse Dijon mustard, honey, brown sugar, and olive oil; drizzle the mixture over the veggies and toss to combine.
Season the coated veggies with salt and pepper, and bake in a 425 degree oven for 20 minutes.
Remove from oven and garnish with fresh chopped sage; serve immediately.