Place the chopped green cabbage, diced red and green bell peppers, diced green tomatoes, and diced white onion into a heavy-bottomed Dutch oven or large stockpot.

Distribute the pats of unsalted butter evenly over the top of the vegetables.

Sprinkle the granulated sugar, sea salt, and freshly ground black pepper directly over the mixture.

Set the stove to medium-high heat.

As the pot warms, the butter will melt over the vegetables, helping to naturally draw out their juices and marry the flavors.

Stir the mixture frequently with a heavy wooden spoon to ensure none of the vegetables stick or scorch at the bottom of the pot.

After the first 8 to 10 minutes, when the vegetables have begun to release their liquid and soften, reduce the stove temperature to low.

Allow the Chow-Chow to simmer gently, uncovered, for 30 minutes up to an hour, stirring occasionally until the vegetables collapse into a cohesive, deeply savory relish.

Remove the pot from the heat.

Serve the warm Chow-Chow immediately as a vibrant garnish for grilled meats and sausages, spooned heavily over a sandwich, or enjoyed simply as a standalone side dish.

Store any remaining relish in a sealed glass jar in the refrigerator, where the flavors will continue to deepen over time.