Preheat your oven to 400°F.
Pat the 5 oz lamb leg dry and rub with salt, pepper, fresh rosemary, and thyme. Let it rest for 10 minutes to absorb the flavors.
Place the lamb in a roasting pan and roast in the preheated oven until it reaches your desired level of doneness (approximately 18-22 minutes for medium-rare).
Meanwhile, scrub the small potato clean. Dice it into 1/2-inch cubes and toss with 1 tsp olive oil, salt, and pepper.
Spread the potato cubes on a baking sheet and roast in the oven alongside the lamb for about 20-25 minutes, turning once to ensure crispiness.
For the braised cabbage, shred 1 cup of cabbage. In a medium saucepan over medium heat, add the cabbage along with a splash of water, a pinch of salt, and pepper. Cover and simmer for 5-7 minutes until tender but still retaining a slight crunch.
Once the lamb and potatoes are cooked, slice the lamb thinly and serve alongside the crispy potatoes and braised cabbage.
Garnish with additional fresh herbs if desired, and enjoy your balanced, herbaceous meal.