01 -
Warm a big skillet on medium-high. Toss in butter and olive oil, wait till butter melts completely.
02 -
Put mushrooms flat in pan (work in small batches if crowded), sprinkle with ¼ tsp salt. Leave them alone for 3 minutes to get a nice sear.
03 -
Turn mushrooms over and let cook another 2-3 minutes until they're nice and brown, don't stir too much.
04 -
Lower heat to medium-low. Throw in garlic and more oil if pan seems dry. Add half the spinach, cover for 30 seconds, stir it up, then add leftover spinach, cover another 30 seconds.
05 -
Sprinkle in the rest of your salt and squeeze in lemon juice, mix everything together. Dish it up right away.