In a large skillet, brown 1 pound of ground beef for about 5–7 minutes, stirring frequently. Drain excess fat, stir in taco seasoning and 1/4 cup of water, and simmer for another 5 minutes.

In a separate skillet, heat about 1/2 inch of oil over medium-high heat. Fry corn tortillas for about 20 seconds on each side until golden and crispy. Remove with a slotted spoon and drain on paper towels.

Lower heat on the skillet used for the beef. Lay crispy tortillas back in the skillet. Layer 2–3 tablespoons of seasoned beef, a generous amount of Rotel tomatoes, diced onions, and mozzarella cheese.

Cover the skillet and let the tacos sit on low heat for about 1–2 minutes to melt the cheese.

Transfer the tacos to serving plates, garnish with fresh chopped cilantro, and serve with lime wedges and optional toppings.