a charcoal grill; a deep-fryer or deep-fry thermometer
For the marinade: Combine the lemon, lime, cumin, oregano, chili powder, salt and garlic in a large bowl. Add the skirt steak and cover with plastic wrap. Place in the fridge until your grill is preheated.
Preheat a charcoal grill over medium-high heat.
Toss the peppers and onions in a bowl with 2 tablespoons oil, salt and pepper, to taste. Grill the skirt steak and prepared vegetables until the steak is medium-rare and the veggies are tender and charred, about 5 minutes. (It'll cook further in the chimichangas.) Set aside on a plate or platter.
For the salsa: Bring a pot of water to a boil and carefully add the tomatillos. Cook until the tomatillos begin to rupture, about 10 minutes. Drain, shock in an ice bath, and transfer to a blender. Add the jalapenos, garlic, cilantro and salt and pulse until incorporated. Transfer to a container, then cover and chill.
For the tortillas: Mix the flour and 1/4 cup water together to form a paste. Lay the tortillas out and rub some of the paste over the top edges of the tortillas. Divide the meat and veggies in the lower thirds of the tortillas. Fold the sides in, then the bottoms. Roll up and allow to rest on the "glued" seal.
Heat a deep-fryer or large Dutch oven with oil to 375 degrees F.
Carefully lower the chimichangas in the hot oil and cook until golden brown, 3 to 4 minutes.
Drizzle some of the crema on the bottom of a large platter. Top with the chimichangas, more crema, tomatillo salsa and cilantro.