Preheat the oven and cook the waffle fries according to package instructions, typically at 425°F (220°C) for 20-25 minutes. Toss the fries in buffalo sauce and keep warm.
Heat 2 tablespoons of oil in a large skillet over medium heat. Add the diced onion and sauté for 3-4 minutes until softened. Add the ground beef and cook for 5-7 minutes until browned. Stir in taco seasoning and simmer for a few minutes.
While the beef is cooking, dice the tomato, avocado, and chop the scallions. Mix the Monterey Jack and cheddar cheese in a bowl.
Warm the tortillas in a dry skillet or wrap them in foil and place in the oven for a few minutes.
Assemble the tacos by adding seasoned beef to each tortilla, followed by the cheese, diced tomatoes, scallions, and avocado. Add a dollop of sour cream if desired.
Serve the tacos with buffalo fries on the side, and enjoy with extra buffalo sauce or ranch dressing for dipping.
Notes
For a spicier kick, add jalapeños or extra buffalo sauce to the tacos.