3 plum tomatoes
Cut up lamb into bite-sized pieces and marinate with the garlic, mint, thyme, oregano, lemon juice, and a fair bit of olive oil.
(From Cowcatcher's original post in somethingawful.com Goons With Spoons forum:)
-------I strongly suggest eyeballing the amount of ingredients you toss into the bowl, it's really hard to screw up this dish. Be aware that two moderately hungry people can go trough a large dish of Arni Kleftiko in about five minutes. Despite its looks, it's a very light dish. I've never seen leftover Arni Kleftiko, and neither will you. Mind you, it's still Greek cuisine, and the taste might be too strong to those who never had any before.
I found that inexpensive Canadian feta works well with this dish, Greek feta (especially goat or sheep milk feta, if you're a fan of strong taste) would be ideal, avoid Macedonian feta as it will melt right away. When buying, look for a hard, porous cheese that crumbles when cut. Macedonian feta is soft and has a solid surface.
You may get a different piece of lamb if you prefer more meat (although this dish works well with very little lamb), but the only substitute for lamb that should be used here is tender young goat. Beef just doesn't cut it.
Chop up tomatoes, potatoes, onions, feta, bread and lamb into half-inch cubes. You can't make carrots into cubes, so cut them normally. Take a big casserole dish or something similar and oil it up. Make sure you spread the oil all the way to the top. Now you want to start tossing in ingredients, but make sure they're mixed in nice and even (you can't just toss them like a salad once they're all in the bowl). Apply spices and salt as you go. Squeeze some lemon in there for good measure.
Stick it in an oven warmed up to 450 degrees for 45 minutes. Depending on your oven, it may take more time, but once potatoes are done (stick a toothpick in them to check) the dish is ready. Don't worry about the juices in the bowl (which may reach up to half the bowl height sometime). Just leave the cover off when serving, and they will evaporate within minutes. Never, ever serve cold.
That's it! Serve with some traditional horiatiki salata and a small piece of baklava for desert.