Trim and clean the green onions: cut off the root ends and the very top 1/2 inch of the dark green tips if wilted. Rinse under cold water to remove grit, then pat dry. Cut the green onions into 2–3 inch lengths on a diagonal, keeping white and green parts together.

Mince garlic

Peel and finely mince the garlic cloves (or press through a garlic press). Set aside.

Heat pan

Place a large skillet or cast-iron pan over medium heat. Add the butter and olive oil and let the butter melt and begin to foam but not brown, about 1 minute.

Sauté garlic

Add the minced garlic to the pan and sauté for 20–30 seconds until fragrant, stirring continuously to prevent burning.

Cook green onions

Add the prepared green onions in a single layer as much as possible. Cook, stirring occasionally, for 3–5 minutes until the white parts are tender and lightly browned and the green parts are wilted but still bright. If the pan gets very dry, add a splash of water (1–2 tsp) to help steam and soften them.

Season

Season with kosher salt (start with 1/2 tsp of the measured salt and adjust), freshly ground black pepper, red pepper flakes, and the teaspoon of soy sauce. Squeeze the juice of half a lemon over the green onions and toss to combine. Taste and add more salt if needed (using the remaining measured salt).

Finish

Cook for an additional 30–60 seconds to let flavors meld, then remove from heat. Stir in optional toasted sesame seeds and chopped herbs if using. Transfer to a serving dish.

Serving suggestions

Serve the sautéed green onions hot as a side for grilled meats, fish, or tofu; use as a topping for rice bowls, noodles, or tacos; or incorporate into omelets and frittatas.

Leftovers can be refrigerated in an airtight container for up to 3 days and gently reheated in a skillet over low heat.