For the marinade: Whisk together the orange juice, oil, soy sauce, vinegar, lime juice, cilantro, cumin, garlic, jalapenos, 1/2 teaspoon salt and 1/4 teaspoon pepper in a medium bowl.
For the chimichangas: Pour the marinade over the steak in a shallow baking dish and let marinate at room temperature for 30 minutes or in the refrigerator for up to 2 hours. Bring the steak to room temperature before cooking.
When the steak is almost ready, heat 1 of the tablespoons oil and the butter in a large skillet over medium-high heat. Add the onions, green and red peppers and a pinch of salt and cook until tender and slightly charred, about 5 minutes. Set aside.
Transfer the steak from the marinade to a plate. Generously sprinkle both sides with salt and pepper.
Preheat the remaining tablespoon oil in a large cast-iron skillet over high heat. Add the steak and cook for 5 to 7 minutes per side for medium doneness, or until the desired level of doneness is reached. Remove from the heat and let rest for 10 minutes. Thinly slice the steak against the grain or dice it into small pieces, if you prefer.
For the assembly: Place a tortilla on a work surface. Place a few slices of steak in the center, followed by 1/2 cup of the onions and peppers. Fold up the sides of the tortilla and then roll up from the bottom to form a tight burrito. Skewer the edges with toothpicks to hold them together. Repeat with the remaining tortillas, steak, and onions and peppers.
Add enough oil to a deep, heavy skillet to come about 1 inch up the side and heat over medium-high heat. When the oil is hot, carefully add the burritos in 2 batches. Cook on both sides until golden brown, about 1 minute per side. Transfer the chimichangas to a wire rack set over a rimmed baking sheet to drain.
Remove the toothpicks from the chimichangas, sprinkle with the cilantro and serve with Queso Cheese Sauce.
Queso Cheese Sauce:
Place the cheese, milk, chilies, butter and House Seasoning in a saucepan. Heat, stirring often, over medium heat until the cheese is melted, about 5 minutes. If the sauce is too thick, stir in more milk 1 tablespoon at a time. Season with salt, if needed.
Miss Brown’s House Seasoning
Stir together the garlic powder, onion powder, paprika, salt and pepper in a small bowl.
Miss Brown’s House Seasoning can be made in a large batch and stored in an airtight container at room temperature for about 3 months.