1. In 5-quart Dutch oven over medium-high heat, in hot salad oil, cook lamb-breast pieces, a few at a time, until browned on all sides, removing pieces to bowl as they brown.
2. In drippings remaining in Dutch oven, over medium heat, cook onions until lightly browned, stirring occasionally. Return lamb pieces to Dutch oven; add wine, salt, thyme, and 1 3/4 cups water; over high heat, heat to boiling. Reduce heat to low; cover and simmer 1/2 to 2 hours, until lamb is fork-tender. Skim fat from liquid in Dutch oven.
3. Add frozen vegetables; over high heat, heat to boiling. Reduce heat to low; cover and simmer 10 minutes or until vegetables are tender, stirring with fork to break up vegetables.
4. In cup, stir flour and 2 tablespoons water until smooth. Gradually stir flour mixture into simmering liquid in Dutch oven; cook, stirring frequently, until gravy thickens slightly.