Suckling lamb is generally slow roasted but can also be braised. Because of its mild flavor, avoid overwhelming it with strong seasonings. A simple rub of olive oil and salt, plus one or two other seasonings works well. Consider using garlic, sweet paprika, lemon, fresh herbs (rosemary, sage, and/or thyme), and/or black pepper.
New potatoes are the most traditional side dish for roast suckling lamb. For an extra treat, sauté or roast the potatoes in rendered lamb fat.