Peel and chop into sweet potato cubes (or whatever shape you desire). Add water upto level of potatoes in a pan and cook on low heat for about 10 mins (covered lid) until sweet potatoes are tender.
Chop the red onion, garlic cloves and jalapenos. Add all the seasonings to the chopped vegetables - 1/2 tbsp of chillie flakes, chilli powder and salt, and 1/2 tsp of turmeric powder. Mix all the seasonings well with the chopped vegetables.
Add one tbsp of oil to a pan on medium heat, and add the seasoned vegetables.
After they are cooked for about 5 minutes on medium heat uncovered, add the sweet potatoes. Mix well and cook on low flame, with a lid on for 5-10 minutes.
Once the onions have cooked, you can optionally add a tsp of curry powder and maldive fish powder for more flavor
Mix well and turn of flame. Add more salt to taste (maybe 1/2 tsp more).
Notes
Note: This recipe is already spicy, so green chillies can be omitted easily. Add less chilli flakes / powder to reduce spiciness