Set a 10- to 12-inch frying pan over medium heat. When pan is hot, salad oil,cumin seed, and mustard seed. Shake pan often until seeds sizzle and begin to pop, 30 to 60 seconds. Add shallots and stir until limp, about 2 minutes. Stir in curry powder and hot chili flakes.
Add beans to pan. Stir beans until coated with seasonings and hot, 2 to 3 minutes. Add salt and pepper to taste.