For ground beef: In a skillet, heat oil over medium high heat. Add onions, sauté until light and translucent, about 3 minutes. Add tomatoes, garlic cloves and serrano chile. Continue cooking for an additional 3 minutes, stirring occasionally. Add ground beef, breaking up with a spoon. Cook until beef is no longer pink and fully cooked. Reduce heat to low. Add salt, pepper, chili powder, cumin, and oregano stir to combine and allow to simmer for 5 minutes.

For gorditas: In a bowl add masa harina and salt. Slowly add warm water, begin mixing with your hands to create a dough. If the dough feels dry, add more warm water by mixing with your hands until the dough comes together.

Divide the dough evenly and hand shape into 8 balls. Place on a baking sheet and cover with a moist kitchen towel or moist paper towels, this helps prevent the dough from becoming dry.

Heat a comal or large skillet over medium-high heat. Line a tortilla press or large glass with plastic film. Place one masa ball in a tortilla press. Gently press to form your gordita or press down on glass to form a gordita. The gordita should be thicker than a corn tortilla, about 3-4 inches in diameter. Return the gordita to the baking sheet, cover with a moist towel and continue shaping remaining gorditas.

Drizzle comal or skillet with a 1 tablespoon oil and place gorditas on hot comal or skillet a few at a time. Cook about 2 minutes, flip, and continue cooking an additional 3 minutes, until light brown spots appear on the gordita.

Remove gorditas, place on a plate and cover with a towel. Continue cooking remaining gorditas, add remaining 1 tablespoon of oil if needed.

Carefully with a knife cut a slit down each warm gordita to create a pocket to add filling.

Fill with ground beef, lettuce, and tomato. Serve with salsa.