One of life's ultimate comfort foods. Use a large butterflied leg of lamb, BBQ/roast one night and use the left overs the next night. The "left overs" are always more popular in our household.
Saute the capsicum and onion in a little olive oil until soft (about 5 minutes). Add garlic and chilli (you won't feel any heat but it boosts the flavour) and saute for 1-2 minutes. Add tomatoes, season with salt and pepper. Saute over low heat for 5 minutes. Set aside.
Roughly chop potatoes. Boil in salted water until cooked. Drain water. Mash roughly then add milk, extra garlic and season and mash until quite smooth.
Heat oven to 180C. Layer lamb and rosemary on the base of your saute or roasting pan. Cover with tomato mixture including optional peas. Cover with potatoes evenly. Cook in hot oven for 30 minutes.
If not using left overs, you'll need to dice and saute the lamb for 5-10 minutes so the excess juices come out and can be drained. Otherwise there will be a soup under the potato. You can also use the more traditional lamb mince. Make sure you brown off and drain the excess juices.