1-Step 1: Gather and prep your ingredientsStart by getting everything ready before you turn on the stove. Measure out 1 and 1/2 cups white wine vinegar, 1 and 1/2 cups white sugar, and the optional 1 tablespoon hot pepper flakes. Then wash the peppers and onions well so they are clean and ready for chopping.Next, dice the 2 red bell peppers, 2 green bell peppers, and 2 sweet onions into 1/4-inch pieces. That size works well because it gives you a relish that is easy to scoop and spoon onto food. If you prefer a chunkier texture, you can go up to 1/2-inch pieces, but stay close to the smaller side for the best classic result.

2-Step 2: Start the pickling syrupPour the vinegar and sugar into a pot. Set the heat to high and bring the mixture to a boil. Stir now and then so the sugar dissolves evenly and does not stick to the bottom.If you are using hot pepper flakes, add them once the liquid begins to boil. This gives the flakes time to bloom in the hot syrup and spread their heat through the relish. Be careful here, because vinegar fumes can be strong. Open a window or use your vent fan so the smell does not bother you while the pot is bubbling.When the vinegar hits the heat, the smell can get strong fast, so I always keep the kitchen vent on and stand a little back from the pot.

3-Step 3: Add the vegetablesOnce the syrup is boiling, add the diced peppers and onions right into the pot. Stir well so every piece gets coated. This is the part where the relish starts to take on its color and shape. The vegetables will soften a bit, but they should still have some texture when the simmering time is done.Lower the heat to a simmer and let everything cook for about 10 minutes. Stir a few times during this stage so the mixture heats evenly. The peppers will brighten, the onions will turn tender, and the liquid will smell sweet, tangy, and inviting.

4-Step 4: Watch for the right textureAfter about 10 minutes, check the relish. It should look glossy and lightly softened, with the syrup slightly reduced. If you like it softer, you can give it another minute or two, but do not cook it so long that the vegetables lose too much color and crunch.This recipe is meant to stay lively and fresh, so a short simmer is best. The contrast between sweet liquid and crisp-tender vegetables is what makes this pepper onion relish recipe stand out.

5-Step 5: Serve hot or coldWhen the relish is done, you can serve it right away while it is warm, or let it cool and serve it cold. Both ways taste great. Warm relish feels cozy on grilled meats and sandwiches, while chilled relish is especially nice on burgers, hot dogs, and snack boards.If you are making this ahead, let it cool fully before storing it in clean jars or containers. The flavor deepens as it sits in the liquid. That is one reason this pickled relish recipe is so handy for meal prep.