Entree: United States – Rocky Mountain United States – Colorado Lamb

Serving Size: 6

Approximate Time

Prep 40 min

Cook 1 hr 15 min

Additional 20 min

Total 2 hrs 15 min

Ingredients

- 1 bone-in leg of lamb, approx. 3 lb (1.36 kg), trimmed
- 3 tbsp (45 ml) extra-virgin olive oil, divided
- 2 tbsp (30 ml) Dijon mustard
- 3 tbsp (45 ml) chopped fresh rosemary
- 2 tbsp (30 ml) chopped fresh thyme
- 4 cloves garlic, minced
- 1 lemon, zested and halved (zest and juice)
- 1 1/2 tsp (8 g) kosher salt
- 1 tsp (2 g) freshly ground black pepper
- 1 1/2 lb (680 g) fingerling potatoes, halved lengthwise
- 1 lb (454 g) mixed root vegetables (carrots, parsnips), cut into 1-inch (2.5 cm) pieces
- 1 lb (454 g) asparagus, woody ends trimmed
- 2 tbsp (28 g) unsalted butter
- 1 small shallot, minced
- 1/2 cup (120 ml) dry red wine (optional, for pan sauce)
- 1/2 cup (120 ml) chicken or beef broth
- 1 tsp (5 ml) honey (for root vegetables)
- Additional salt and pepper as needed

Instructions

Short Description:
Roasted Colorado Lamb rubbed with rosemary, thyme, garlic, and lemon, served with roasted fingerling potatoes and seasonal vegetables (grilled asparagus and honey-roasted root vegetables) and a simple red-wine pan sauce. A complete, hearty Rocky Mountain main course perfect for 4–6 people.

Regional Notes:
This Rocky Mountain version uses classic Colorado herb flavors—fresh rosemary and thyme—and combines oven-roasting with a quick grill for seasonal produce (asparagus in spring, mixed root vegetables in cooler months). The method highlights local lamb raised in Colorado and pairs it with rustic roasted potatoes and a pan sauce that nods to Western grilling and roasting traditions.

1. Remove the lamb from the refrigerator 30–45 minutes before cooking to come toward room temperature. Preheat oven to 400°F (200°C). Arrange a rack in the center.
2. In a small bowl, mix 2 tbsp (30 ml) olive oil, Dijon mustard, chopped rosemary, chopped thyme, minced garlic, lemon zest, 1 tsp (6 g) kosher salt, and 1/2 tsp (1 g) black pepper to form a paste. Rub the paste all over the leg of lamb, pressing to adhere.
3. Toss fingerling potatoes and root vegetables with 1 tbsp (15 ml) olive oil, 1/2 tsp (3 g) kosher salt, 1/2 tsp (1 g) black pepper, and 1 tsp (5 ml) honey for the root vegetables. Spread the potatoes and root vegetables in a single layer on a large rimmed baking sheet or roasting pan.
4. Heat a large ovenproof skillet (cast iron preferred) over medium-high heat with the remaining 1 tbsp (15 ml) olive oil. Sear the leg of lamb 2–3 minutes per side until nicely browned (including ends). Transfer the seared lamb to the roasting pan, nestling it among the potatoes and root vegetables, fat side up.
5. Roast in the preheated oven until an instant-read thermometer inserted into the thickest part of the meat (not touching bone) reads 125–130°F (52–54°C) for medium-rare or 135–140°F (57–60°C) for medium. As a guideline, expect about 20–25 minutes per pound (45–55 minutes for a 3 lb roast), but use internal temperature for accuracy. Stir the vegetables once halfway through roasting for even browning.
6. While the lamb roasts, prepare the asparagus for grilling: toss asparagus with a light drizzle of olive oil and a pinch of salt and pepper. Preheat a grill or grill pan to high.
7. When the lamb is 10–15 minutes from your target temperature, grill the asparagus over high heat 2–4 minutes per side until char marks appear and stalks are tender-crisp. If you prefer, roast asparagus in the oven alongside the vegetables for 8–10 minutes at 400°F (200°C) instead.
8. Remove the lamb from the oven when it reaches the desired internal temperature. Transfer the lamb to a cutting board and tent loosely with foil. Let rest 15–20 minutes (the internal temperature will rise a few degrees).
9. While the lamb rests, make the pan sauce: wipe the skillet used for searing if very charred, then return it to medium heat. Add butter and the minced shallot; sauté 1–2 minutes until translucent. Deglaze with red wine, scraping up browned bits; simmer until reduced by half (about 2–3 minutes). Add broth and a sprig of fresh rosemary or thyme, simmer 3–4 minutes until slightly thickened. Taste and season with salt and pepper. Strain if desired.
10. Slice the rested lamb against the grain into 1/4–1/2 inch (6–12 mm) slices. Arrange on a serving platter with roasted potatoes, root vegetables, and grilled asparagus. Spoon pan sauce over the lamb or serve on the side. Garnish with a few fresh rosemary or thyme sprigs and a squeeze of lemon juice if desired.
11. Serve immediately; leftover lamb stores refrigerated up to 3 days.