Step 1 Slice the beef as thinly as possible, then set it aside.
Step 2 Combine the coriander, cumin, cinnamon, turmeric, cayenne and the salt in a small bowl. Set aside.
Step 3Melt the butter in a large skillet over medium-high heat. Add the shallots and cook, stirring until golden brown, about 2 minutes. Add the garlic and the ginger and cook, stirring until the mixture is very fragrant, about 1 to 2 minutes. Add the combined spices and cook 1 minute. Then add the beef, brown sugar, vinegar and beef broth. Bring to a simmer and cook until the flavors are well blended, 6 to 8 minutes.