In a large skillet, heat the vegetable oil over medium-high heat. Add the chopped onion and sauté until golden brown.

Stir in the minced garlic, ginger, and green chilies, cooking for an additional 2-3 minutes until fragrant.

In a bowl, combine the beef cubes with cumin, coriander, turmeric, garam masala, red chili powder, and salt. Mix well to coat the beef evenly with the spices.

Add the spiced beef to the skillet and brown on all sides for about 5-7 minutes.

Transfer the browned beef and onion mixture to the slow cooker. Add the diced tomatoes, beef broth, and coconut milk, stirring to combine.

Cover and cook on low for 6-8 hours or on high for 3-4 hours, until the beef is tender and fully cooked.

Once cooked, taste and adjust seasoning if necessary. Garnish with fresh cilantro before serving.