1. In a small bowl, combine the chopped tomatoes, white onion, cilantro, jalapeño, and lime juice. Set aside.

2. Heat a large skillet over medium-high heat and cook the diced yellow onion in a little butter or oil until softened.

3. Add the garlic and stir for about 30 seconds until fragrant.

4. Add the ground beef and cook, breaking it up with a spatula, until browned and fully cooked.

5. Stir in the taco seasoning, tomato paste, salt, and black pepper until the beef is evenly coated.

6. Sprinkle the cheddar and Monterey Jack over the beef, then chop and fold everything together until the cheese is fully melted.

7. Split the hoagie rolls and spread them with butter, then toast until lightly golden.

8. Spread mayonnaise or crema inside each roll if using.

9. Fill each roll with the cheesy beef mixture.

10. Top with the fresh tomato mixture and extra jalapeño slices if desired.

11. Serve immediately while hot and melty.