Place the tomatoes, jalapeño, garlic, and onion in a cast iron skillet over medium-high heat. Let them cook for 4-5 minutes on each side or until charred all over. (You can also do this in the oven under a broiler.)
Add all of the charred veggies, oregano, cumin, ground coriander, salt and pepper to a blender. Process it until you get a smooth mixture. Season with more salt and pepper, to taste. Set it aside.
Place the potatoes in a microwave-safe container. Cover them with water. Microwave for 7 minutes. Strain the potatoes and set them aside.
Add the vegetable oil to a large pot over medium heat. Add the potatoes and stir. Let the potatoes cook for 6-7 minutes, stirring occasionally, until tender.
Add the beef to the pan and let it cook for 8-10 minutes, stirring often, until browned. Season with the salt and pepper.
Pour in the blended sauce and stir to combine. Let it simmer, stirring occasionally, for 15 to 20 minutes.
Stir the cheese into the pot. Let it melt completely. Adjust the seasoning with more salt and pepper, to taste. Serve immediately.
