Step 1

Preheat oven to 200°C. Heat a large non-stick frying pan over high heat. Add the beef and cook, stirring with a wooden spoon to break up any lumps, for 5 minutes or until beef changes colour. Add the taco seasoning and cook, stirring, for 1 minute or until aromatic. Add the tomato. Reduce heat to medium-low and cook, stirring occasionally, for 15 minutes or until the beef mixture thickens slightly. Remove from heat.

Step 2

Meanwhile, cook the sweet potato and potato in a large saucepan of salted boiling water for 10 minutes or until tender. Drain well. Return to the pan with butter. Use a potato masher or fork to mash until smooth. Add milk and stir until well combined. Taste and season with salt and pepper.

Step 3

Brush four 185ml (3/4-cup) capacity non-stick Texas muffin pans with oil to lightly grease. Line the bases and sides of the prepared holes with tortillas. Bake in preheated oven for 10 minutes or until crisp. Remove from oven. Spoon the beef mixture evenly among tortilla cases. Top with sweet-potato mixture. Bake in oven for a further 10 minutes or until heated through and the top is lightly brown. Serve with steamed beans, if desired.