In a bowl, whisk together 2 tablespoons oil, garlic, cumin, coriander, salt, pepper, and vinegar. Add lamb and toss to coat. Marinate at room temperature for 15 minutes or cover and refrigerate to marinate up to 24 hours.

In a large skillet or cast iron pan over medium-high heat, add remaining 2 tablespoons oil. Add lamb, in batches if necessary, and cook until browned approximately 5 minutes. Transfer lamb to a plate and tent with foil; continue cooking remaining lamb and transfer to plate.

Add onion and cook, stirring often, 3 to 5 minutes. Add ½ cup water and deglaze pan, scraping up any brown bits, and cook until most of the water is evaporated.

Add lamb back to pan and toss with onion.

Serve topped with pomegranate seeds, pistachio, and optional yogurt and mint.