1. Heat a large frying pan, or a casserole dish if you’re cooking the chilli on the hob. When warm, drizzle in 1 tbsp oil then add the beef strips. Fry for 6-8 mins, stirring every now and then, till browned.
2. While the beef cooks, peel and finely chop the onion and garlic. If you’re using the chilli, finely chop it, removing the seeds for less heat or keeping them in if you want more of a kick.
3. From this point on, follow the instructions for either the slow cooker or hob method.
4. In the slow cooker:
Lift the beef out of the pan and in to a 3½ ltr slow cooker. Trim, peel and coarsely grate the carrots. Peel the sweet potatoes and chop them into 1-2cm cubes. Drain and rinse the beans.
5. Put the onion, garlic, chilli (if using), carrots, sweet potatoes and beans into the slow cooker. Pour in the chopped tomatoes, then fill the tin with cold water (about 400ml) and pour that in too. Drop in the cinnamon stick with 1 tsp cacao powder.
6. Add a pinch of salt and pepper and mix together. Pop the lid on the slow cooker and cook on medium for about 6 hrs. For a faster chilli, set to high for 3-4 hours or go slow on low for 8-10 hours.
7. While the chilli cooks, finely chop the coriander stalks and tear the leaves. Zest and juice the lime into a small bowl.
8. When your chilli is cooked, add the coriander stalks, lime zest and juice. Taste and add more salt, pepper or cacao if necessary. Spoon into 4 warm bowls, scatter over the coriander leaves to garnish, and serve.
9. On the hob:
Lift the beef out of the casserole dish and into a bowl. Set the dish back on the hob. Drizzle in 1 tbsp oil and add the chopped onion. Cook for 5 mins, stirring now and then, till the onion is soft.
10. While the onion is cooking, trim, peel and coarsely grate the carrots. Peel the sweet potatoes and chop them into 1-2 cm cubes.
11. After the onion has cooked for 5 mins, add the garlic, chilli and carrots and cook for 2 mins, stirring. Drain and rinse the beans.
12. Add the beef back to the pan. Pour in the chopped tomatoes and add 500ml cold water. Add the sweet potatoes and drop in the cinnamon stick.
13. Add the mixed beans and 1 tsp raw cacao powder with a good pinch of salt and pepper and mix well. Turn the heat to low and put the lid on. Cook for 1 hr, stirring now and then.
14. While the chilli is cooking, finely chop the coriander stalks and tear the leaves. Zest and juice the lime into a small bowl.
15. When your chilli is cooked, add in the coriander stalks, lime zest and juice. Taste and add more salt, pepper or cacao if necessary. Spoon into 4 warm bowls and top with the coriander leaves to serve.