Daging Sapi Ponzu Mentega

Bahan-bahan (2 porsi)

• ½ lb thinly sliced beef (such as ribeye)
• 2 cloves garlic
• 1 bunch komatsuna ((3 oz, 85 g; or spinach))
• 1 package maitake mushrooms ((3.5 oz, 100 g; or any kind you like))
• 1 Tbsp neutral oil
• ¼ tsp Diamond Crystal kosher salt ((divided))
• ¼ tsp freshly ground black pepper ((divided))
• 1 Tbsp unsalted butter
• 4 Tbsp ponzu
• ½ tsp toasted white sesame seeds ((optional, for garnish))