Grilled Onion Recipe

Peel and slice

Peel the outer papery layers from the onions. Trim root and stem ends to create relatively flat surfaces, but leave enough of the root end intact so the onion layers hold together. Slice each onion crosswise into 1/2-inch thick rounds (about 4–6 slices per onion depending on size). If any slices fall apart, reserve loose layers to grill separately.

Dry and oil

Pat the onion slices dry with paper towels to remove excess moisture (this helps achieve good charring). In a shallow bowl or on a tray, brush both sides of each slice with the olive oil. Sprinkle both sides evenly with kosher salt, black pepper, and garlic powder if using.

Preheat grill

Preheat an outdoor grill or grill pan over medium-high heat (about 400–450°F / 200–230°C). If using a gas grill, allow 10–12 minutes for the grates to get hot; for a charcoal grill wait until coals are covered with light ash. Oil the grates lightly or use a well-seasoned grill pan to prevent sticking.

Grill onions

Place the oiled onion slices directly on the hot grates. Grill without moving for 3–5 minutes per side, until distinct grill marks form and the onions are tender when pierced with a fork. If slices are thicker or grill heat is lower, allow up to 6–8 minutes per side. For loose layers, use a grill basket or a piece of foil to keep them from falling through the grates.

Finish and rest

Transfer the grilled onions to a plate. While still warm, taste and adjust seasoning if needed. If using lemon juice or balsamic glaze, drizzle it lightly over the slices. Let onions rest 2–3 minutes to allow juices to redistribute.

Arrange grilled onion slices on a serving platter. Sprinkle with chopped fresh parsley if desired. Serve warm as a side dish, burger topping, or incorporated into sandwiches, salads, or grain bowls.