Prepare the ingredients: drain canned corn or measure 4 cups if using frozen or fresh; if using fresh, cut kernels from the cobs. Finely dice 1 small onion. Strip the leaves from 2 sprigs fresh thyme and discard the stems; set the leaves aside.

Place a medium saucepan over medium heat and add 2 tablespoons butter. Melt the butter.

Add the diced onion to the pan and cook, stirring occasionally, until the onion is soft and translucent, about 4–5 minutes.

Add 4 cups corn kernels to the pan and cook, stirring, until the corn is warmed through and any excess liquid has mostly evaporated, about 2–4 minutes (may take a little longer if the corn is frozen).

Sprinkle 2 tablespoons all-purpose flour over the corn and onions, stir to coat, and cook for 1 minute to remove the raw flour taste.

Slowly pour in 1/2 cup heavy cream and 3/4 cup milk while stirring to combine and smooth any lumps. Bring the mixture to a gentle simmer over medium-low heat.

Stir in 1/2 teaspoon salt, 1/4 teaspoon ground black pepper, and the reserved thyme leaves. Simmer, stirring occasionally, until the sauce thickens, about 3–5 minutes.

Remove the pan from the heat. Use an immersion blender to blend roughly half of the mixture in the pot for a slightly chunky texture, or blend all of it for a creamier consistency. Blend carefully until you reach the desired texture.

Serve warm.