Green chilli stew

Ingredients

• 2 tablespoons olive oil
• 1 kilogram beef chuck steak, cut into 3cm cubes
• 1 brown onion (200g), sliced thinly
• 2 cloves garlic, sliced thinly
• 2 teaspoons ground cumin
• 2 fresh long green chillies, seeded, sliced thinly
• 2 cups (500ml) beef stock
• 1 tablespoon tomato paste
• 3 egg tomatoes (270g), chopped coarsely
• 500 grams tiny new potatoes, halved
• 4 flour tortillas
• 1/4 cup coarsely chopped fresh coriander