Clean mushrooms with a damp towel or quick rinse and trim tough stems. Roughly chop larger mushrooms so pieces are bite-sized (about 1/2–1 inch). Pat dry.

Heat a large skillet or sauté pan over medium-high heat. Add vegetable oil and butter. When butter stops foaming, add chopped mushrooms in a single layer (work in batches if necessary to avoid steaming). Let mushrooms brown undisturbed 3–4 minutes, then stir and continue browning another 3–4 minutes until deeply golden.

Add the chopped onion and continue to sauté 4–5 minutes until the onion is softened and translucent and mushrooms have released and started to reabsorb their juices.

Stir in minced garlic, sea salt and black pepper and cook 30–45 seconds until fragrant.

Vegetables & aromatics

Add the thinly sliced cabbage to the pan with the mushrooms and onion. Toss and cook 3–4 minutes until cabbage wilts but still has some bite.

Stir in the chopped tomatillos and cook 2–3 minutes until they begin to soften and release bright, tangy juices.

Chili paste & sauce

In a small bowl, whisk together the chili paste, tomato paste, soy sauce, rice vinegar, brown sugar and vegetable stock until smooth.

Pour the sauce into the pan with the mushrooms and vegetables. Stir to combine, scraping up any browned bits from the bottom of the pan. Bring to a gentle simmer and cook 4–6 minutes until sauce thickens slightly and coats the mushrooms.

Taste and adjust seasoning; add more chili paste for heat, a pinch more sugar for balance, or a splash more soy sauce or salt if needed.

Finishing

Remove pan from heat. Stir in the chopped cilantro and lime juice, and drizzle sesame oil if using. Toss to combine.

Garnish with sliced green onions and toasted sesame seeds. Serve warm.

Serve suggestions: this mushroom mix works well over steamed rice, in a warm tortilla as a filling, or alongside grilled proteins. Leftovers keep 3–4 days refrigerated in an airtight container.