Cut kernels from corn; set aside.
Heat oil in a large nonstick skillet over medium until shimmering. Cook chile, ginger, garlic, and 1 sliced scallion, tossing, until softened and fragrant, 1–2 minutes.
Add turmeric and cook, stirring frequently, just until darkened and fragrant, about 30 seconds.
Add reserved corn and increase heat to medium-high. Cook, tossing occasionally, until corn is beginning to lightly brown, about 3 minutes.
Add grains and cook, tossing often, until heated through and beginning to crisp around the edges, about 2 minutes.
Add ½ cup coconut milk; season with salt. Bring to a simmer and cook, adding 1–2 Tbsp. water if needed to loosen, until flavors have melded, about 3 minutes.
Transfer corn mixture to a plate. Drizzle with more coconut milk, then top with crispy onions and sliced scallions. Serve with lime wedges alongside for squeezing over.