Reserve 2 teaspoons taco seasoning for potatoes. Crumble mince into a 2.5 L (10 cup) microwave-safe dish. Add onion, capsicum and garlic and stir to combine. Cover, microwave, on 100, stirring halfway through, for 4 minutes.
Add the beans, tomato paste, chilli powder and 60ml (1/4 cup) water to the mince mixture. Cover, microwave, for a further 3 minutes or until hot. Set aside.