Melt butter in a small pan. Add onion and garlic; sauté for 2–3 minutes. Let cool slightly.
Id=”instruction-step-2″>2. Whisk egg and milk in a microwave-safe mug. Add salt and pepper. <
Id=”instruction-step-3″>3. Stir in sautéed onion mixture, spinach, mushrooms, feta, and half the Cheddar.
Id=”instruction-step-4″>4. Microwave on high for 1 minute. Stir gently.
Id=”instruction-step-5″>5. Microwave another 1½ to 2 minutes until center is set.
D=”instruction-step-6″>6. Top with remaining cheese. Let sit 30 seconds before eating.
