Scale

Here’s everything you’ll need to make these spicy refrigerator-pickled onions and jalapeños.

1 large red onion, thinly sliced — Develops a delicious sweet-tart flavor and vibrant color as it pickles.
2 fresh jalapeños, thinly sliced — Add fresh chile flavor, crunch, and heat.
4 garlic cloves, thinly sliced — Provide bold savory garlic flavor throughout the jar.
1 cup white vinegar — Creates the bright, tangy base of the pickling brine.
1 cup water — Balances the acidity of the vinegar.
1 tbsp kosher or pickling salt — Seasons the vegetables and brine.
1 tbsp sugar — Adds just enough sweetness to balance the vinegar and chile heat.
1 tsp red pepper flakes — Reinforce the jalapeños with additional heat.
½ tsp black peppercorns — Add subtle peppery warmth.
½ tsp mustard seeds — Provide a classic savory pickling note.
½ tsp dried oregano — Adds a mild herbal flavor that works especially well with onions and jalapeños.
1 small dried chili pepper, optional — Adds another layer of chile flavor and heat.
¼ cup fresh cilantro, optional — Adds a fresh herbal finish after the jar has cooled.

This quick refrigerator-pickle recipe requires only a few minutes of active preparation.

Peel the red onion and slice it thinly.

Thinly slice the fresh jalapeños and garlic cloves.

Try to keep the onion and jalapeño slices relatively even so they pickle consistently.

Place the sliced red onion, jalapeños, and garlic into a clean glass jar.

Add the red pepper flakes, black peppercorns, mustard seeds, dried oregano, and optional dried chili pepper.

Distribute the ingredients throughout the jar.

Add the white vinegar, water, kosher or pickling salt, and sugar to a small saucepan.

Place over medium heat.

Stir until the salt and sugar have completely dissolved.

Bring the mixture just to a gentle simmer, then remove the saucepan from the heat.

Carefully pour the warm brine over the red onions, jalapeños, garlic, and spices.

Make sure the vegetables are completely covered with the liquid.

Use a clean spoon to gently press the vegetables beneath the surface.

This also helps release any trapped air bubbles between the onion and jalapeño slices.

Leave the jar uncovered at room temperature until completely cooled.

If you’re using fresh cilantro, add it after the jar has cooled.

Seal the jar tightly and transfer it to the refrigerator.

Allow the vegetables to pickle for at least 4 hours before serving.

For more developed flavor and beautiful color, refrigerate the pickles overnight before serving.

As they rest, the red onions soften slightly while absorbing the spicy, garlicky vinegar brine