Trim the large pieces of fat from the lamb and cut into 2-inch chunks.
Peel the sweet potato and the new potatoes and cut into 2-inch chunks.
On a large rimmed sheet pan (12x17), toss the lamb and the potatoes with the olive oil, then sprinkle the herbs over all and toss until evenly coated.
Add salt and pepper to your liking and toss. (When I make this for my extended family I leave it off altogether and let everyone add their own. My husband loves salt and pepper, so when it's just us, I use it liberally.)
Spread the meat and vegetables out on the tray evenly and scatter the sliced garlic on top.
Slide this into your preheated oven and roast for 20 minutes, tossing halfway through cooking. Meat should be browned. (We like our lamb cooked medium-well. If you want your meat more rare, then start the potatoes and add the meat 5 to 10 minutes later.)
Add the tomatoes and the peas to the sheet pan and cook for an additional 10 minutes.
Gr8 Note About the Lamb Shoulder Chops:The store where I buy my meat had 2 types of shoulder chops, blade and round bone. You want the chops with the round bone, they are easier to work with. Also, you can ask your butcher to cube the meat for you to save time at home.Gr8 Note:If you don't like lamb, try substituting sirloin steak. You may need less, because sirloin is less fatty than lamb. Thanks to one of our Gr8 Friends, Claudia, for asking about this!This nutritional information is only an estimate. We do not guarantee the accuracy of the nutritional information for any recipe on this site.