Using a large dutch oven or similar sized pot, brown the meat and the onions together in a little olive oil. Add some red pepper flakes at this stage if desired. Drain the fat and return to the pan.
Season with the curry powder and other spices.
While over medium heat, add the potatoes and carrots and give a good stir to coat with the spices and fat.
Add the tomatoes, any juices and tomato sauce/paste. Add water if necessary to increase the amount of gravy (some will cook away while the curry simmers).
Bring to a simmer, reduce heat to low and cover. Continue to simmer, stirring occasionally, until the carrots and potatoes are cooked through. Taste and adjust the seasoning, add more tomato sauce, etc.
When the potatoes are about halfway cooked, stir in the peas and raisins.
If serving over rice or pasta, start when the peas are added. The keema will hold while they cook.
Store leftovers in the fridge for about a week. Add a little water to loosen the gravy before reheating.