Toast ancho, guajillo, and arbol chilies in a dry skillet over medium heat for 1 minute, shaking constantly to avoid burning.
Soak toasted chilies in 2 cups hot water for 20 minutes; drain and set aside.
Heat 2 tbsp grapeseed oil in a Dutch oven over medium-high heat. Sear beef in batches until deep golden browned; remove and set aside.
In the same pot, add remaining oil, sauté onion and garlic until translucent.
Add seared beef, remaining chilies (including soaked), beef stock, oregano, cinnamon, cloves, salt, and vinegar. Bring to a simmer, cover, and transfer to a 300°F (150°C) oven.
Braise for 2.5 hours or until beef is fork-tender.
Remove meat and shred. Strain the braising liquid through a fine-mesh sieve; reduce the consomé to 3 cups if needed.
Make chili oil by heating 2 tbsp oil, arbol chilies, and a pinch of salt in a pan for 5 minutes.
Heat corn tortillas in a dry skillet, then quickly dip in chili oil and sear on edges until crisp, about 10 seconds per side.
Serve tacos with shredded beef, Oaxaca cheese dollops, consomé for dipping, and a sprinkle of onion.