In a large skillet over medium-high heat, brown 2 lbs lean ground beef until fully cooked. Drain the excess grease from the skillet. Add 2 packages taco seasoning and the amount of water listed on the taco seasoning packets. Stir well and simmer for 5 minutes until the meat is fully coated and heated through.
Place 1 can (16 oz.) refried beans in a microwave-safe bowl. Heat in 1-minute intervals, stirring between each interval, until the beans are hot and smooth. This should take about 3 minutes.
Spread approximately 2 Tablespoons of the beans onto each flour tortillas. Place the hard taco shell in the middle of the flour tortilla and wrap the flour tortilla up against the crunchy shells.
Place the seasoned ground beef in the center of the crunchy shells.
Top the tacos with 2 cups shredded Mexican cheese, 4 cups shredded lettuce, 2 diced Roma tomatoes, 1 diced onion, and 2 sliced jalapeños.