my normal lamb stew (i used to cook a lot more than i do now) starts with well trimmed lamb meat cut into chunks however big you'd like them. however as much garlic and onions as you'd like (i tend to overdo it). i brown that all and then simmer for some time to make sure it is well done and tender then i add the cut up potatoes, carrot chunks and onions (yes more onions) and enough water to steam those for a half hour and then i add in all the chopped cabbage i can fit in the pot and steam that until it is tender and then add a quart of tomato chunks right at the end. i don't usually thicken this as the potatoes do enough of that for me and i don't normally add a lot of other liquid as i want the broth to mostly be the juices from the vegetables combined with the tomatos. celery or other root vegetables can go in there too at any point as long as they have enough time to finish cooking.
as usual, adjust to taste. sometimes i put less tomato chunks in and other times i add basil or dill or both or ... it is rare that i make the exact same recipe each time. recipe's are like frames to hang other things.