1. For the spicy sauce,place the tomatoes,macha paste,garlic,cumin,oregano and salt in a blender. Add the stock and process until quite smooth.
2. For the meatballs,place the beef,pork,cumin,garlic,salt and a grind of pepper in a bowl. Mix well,then stir in the breadcrumbs,eggs and milk. To check the seasoning,cook a small amount of mixture in a little olive oil and taste it. Form the mince mixture into small walnut-sized balls.
3. Heat a large frying pan with a splash of olive oil over a medium heat. Add the meatballs and brown gently for 2 minutes. Add the sauce and cook gently for 6 minutes,stirring occasionally,or until the sauce starts to thicken. Reduce the heat to medium-low and cook,uncovered,until the sauce reduces to about half its original volume and coats the meatballs (about 5 minutes).
4. Spoon the meatballs onto a serving plate and grate the Manchego or pecorino over the top. Sprinkle with coriander leaves.
*Macha is available fromfireworksfoods.com.au. Once you buy it,you'll use it on everything.
For another delicious,Mexican-inspired dish,try Neil Perry'sking prawns in green salsa.