Make tortillas, if you're using Homemade Tortillas.
Marinate the steak: Spread the jalapenos in a baking dish and press the steak on top. Cover and set aside at room temperature, about 1 hour.
Preheat a grill or grill pan to high. Brush the jalapenos off the steak, pat dry and season with salt and pepper. Grill the steak for 4 to 6 minutes per side for medium-rare. Let rest 10 minutes, then slice.
Assemble the tacos: For each taco, stack 2 tortillas and lay a few pieces of steak in the middle. Top with onion, salsa and cilantro. Top with lime wedges.
Toast the chiles in a dry skillet or saucepan over medium-low heat, shaking the pan, about 2 minutes. Pour 1/2 cup boiling water on top, cover and let soak 15 minutes.
Meanwhile, preheat a grill or grill pan to high. Grill the tomatoes, turning, until charred. Transfer to a food processor. Add the chiles and their soaking water, onion, garlic, oregano, lime juice, sugar and 1 1/4 teaspoons salt; pulse until chunky. Set aside, about 1 hour. Garnish with cilantro.
Put the masa harina in a bowl and gradually stir in 1 cup plus 2 tablespoons warm water with a fork.
Add 3 or 4 more tablespoons water, 1 tablespoon at a time, and mix with your hands until the dough comes together.
Knead until soft and pliable, then gather into a ball, cover with plastic wrap and set aside, 30 minutes.
Roll the dough into Ping-Pong-size balls, moistening your hands with water to keep the dough from sticking. Place the balls on a baking sheet lined with plastic wrap; keep covered with more plastic as you roll the rest of the dough.
First, set a large griddle over two burners; heat one side to medium-low and the other to medium-high (or use two cast-iron skillets).
Cut a circle slightly larger than your tortilla press from a large resealable plastic bag; include the seam of the bag in your circle so that the two circles remain attached on one side.
Place a dough ball between the plastic rounds and flatten in a tortilla press into a 5-inch circle, about 1/8-inch thick. (If you don't have a tortilla press, use a coffee can to flatten the dough.)
Peel off the top piece of plastic; flip the tortilla onto your hand and peel off the bottom piece of plastic.
Ease the tortilla onto the cooler side of the griddle and cook until it is slightly dry around the edges and starts to peel away from the griddle, about 45 seconds. Transfer to the hotter side of the griddle, uncooked-side down. Cook until speckled on the bottom, about 1 minute, then flip and cook until puffed in spots, about 1 more minute. Press and cook the remaining tortillas; stack them in a cloth-lined basket and cover with the cloth, or wrap in foil and keep warm in a 250 degrees F oven.
Courtesy of Aaron Sanchez for Food Network Magazine