- Preheat oven to 300 degrees.
- While the oven is heating begin charring the wood chips in a pan over high heat until they begin to smoke and almost catch on fire (you will want your hood vents on for this step).
- While the wood chips are charring on the stove break the mushrooms into bite-size pieces and set aside in a large mixing bowl.
- For the rajas, cut the onion and poblano peppers into halves. Peel the onion and slice into thin strips (rajas translates to “strips”). For the peppers, remove the seeds and cut out the white veins on the inside. Slice into strips that are the same size as the onion strips.
- Combine the onions, peppers, and mushrooms. Toss with the olive oil and salt. Spread onto a sheet pan.
- Place the mushroom mixture in the top rack of the oven and place the pan of smoking wood chips on the bottom tray and roast for 20 minutes. You just want to par-cook the mushrooms and let them absorb as much of the smoke as possible.
- While the mushrooms are cooking, roast the garlic cloves in a dry sauté pan over medium heat until they are soft and cooked throughout, about five minutes. Smash the garlic with a knife, mince until almost puréed, and fold into the crema or sour cream with a pinch of salt.
- To assemble the tacos, first heat the tortillas in a sauté pan until hot and wrap in a towel to steam while you sear the mushrooms and rajas in a separate sauté pan to caramelize the mushrooms. Check the seasoning of the mushrooms. Take a warm tortilla and spread about a tablespoon of the garlic crema over it. Place about 3 tablespoons of the mushrooms and rajas on top of the garlic crema. Sprinkle as much Cotija and cilantro over the taco as you prefer and eat while still warm.