Preheat the oven: Preheat your oven to 425°F. Line a large sheet pan with parchment paper or foil.
Make the maple glaze: Add the butter, maple syrup, steak seasoning and thyme sprigs to a small saucepan over medium-low heat. Allow the butter to melt. Whisk the mixture until combined.
Pour the glaze over the carrots: Add the carrots to the sheet pan in a single layer. Pour the maple mixture over them and toss until evenly coated.
Roast: Roast the carrots for 20 minutes.
Toss again then continue roasting: Toss the carrots, then continue roasting for 10-15 more minutes, or until the carrots are fork-tender with caramelized edges.
Finish & serve: Toss the hot carrots in the glaze remaining on the sheet pan. Garnish with parsley and serve warm.
Notes
Cut evenly: Slice the carrots into similar-sized pieces so they cook at the same rate.
Use a single layer: Give the carrots room so the edges roast instead of steam.
Expect a thin glaze at first: The maple butter thickens as the carrots roast.
Finish with the glaze: Toss the hot carrots in the maple butter left on the sheet pan before serving.