Heat oil in a large pan over medium high heat. Add the onions and cook until soft and fragrant. Add the cubed sweet potatoes and stir to coat. Add curry paste and stir to coat as well.
Stir in the coconut milk (1 can for a thick curry, 2 for more sauce) and broth to the pan, lower heat and simmer for 10-15 minutes, until the sauce has thickened. add the spinach and stir until wilted.
Add half a cup each of the peanuts and cilantro on top, and the cricket flour. Stir everything in gently. Add a splash of fish sauce to taste.
Serve in bowls over the rice and top with remaining peanuts and cilantro.