Cut kernels from corn cobs and place in a medium bowl.

Using the back of a chef’s knife, scrape milk from cobs into the bowl; discard cobs.

Heat 1 Tbsp. oil in a medium saucepan over medium.

Cook chorizo, stirring occasionally until it starts to get crisp, about 2 minutes.

Carefully pour chorizo oil into a small bowl (use a slotted spoon to hold back chorizo); set chorizo oil aside.

Return chorizo pan to medium heat and add scallions, garlic, chile, 1 Tbsp. olive oil, and ¾ tsp. salt. Cook, stirring occasionally until vegetables are softened but not browned, about 2 minutes.

Add corn kernels and cook, stirring occasionally, until bright yellow and softened, 5–7 minutes.

Remove from heat and let corn mixture cool in pan 5 minutes.

Gently mix in buttermilk and cilantro. Taste and season with more salt if needed.

Season scallops generously with salt.

Heat reserved chorizo oil and remaining 1 Tbsp. olive oil in a large skillet over medium-high until just beginning to smoke.

Cook scallops on one side, reducing heat if they are taking on too much color and moving around in the pan for even browning, until a golden-brown crust forms on the bottom, about 3 minutes.

Reduce heat to medium-low and turn scallops over.

Add butter to the skillet and, using a spoon, baste scallops with butter 30 seconds. Transfer scallops to a plate.

Squeeze halved lime over.

Divide corn mixture among plates and arrange scallops on top. Serve with lime wedges for squeezing over.