Sauté the beef and onion in a skillet until cooked through.
Season the beef with taco seasoning.
Prepare the tortilla chips on baking sheets.
Top chips with refried beans and meat mixture.
Sprinkle shredded cheese over the chips.
Bake in the oven until cheese is melted.
Garnish with diced tomatoes and green onions before serving.
Notes
To store leftovers, cool completely and place in an airtight container in the refrigerator for 4-5 days. For freezing, store the meat separately in a freezer-safe container for up to 3 months.