In a pan, dry roast the dried red chilies, mustard seeds, and cumin seeds for a few minutes until fragrant. Let them cool, then grind them to a fine powder.

In a large bowl, mix the beef with the ground spice mix, vinegar, garlic, ginger, turmeric, cinnamon, and salt. Let it marinate for at least 1 hour, or overnight for better flavor.

In a large pot, heat the oil over medium heat. Add the chopped onions and sauté until they are golden brown.

Add the marinated beef to the pot and cook on high heat for about 5-7 minutes, stirring frequently.

Lower the heat to medium-low, cover the pot, and let it simmer for about 1.5 to 2 hours, or until the beef is tender. Stir occasionally and add a little water if needed to prevent sticking.

Once the beef is tender, check the seasoning and adjust salt or spices as needed. Garnish with fresh cilantro before serving.