1. Make the filling: Heat 2 tablespoons of oil in a skillet over medium-high heat. Brown the ground meat, then add the diced onion and chopped garlic; cook until translucent. Stir in tomato sauce, raisins, pecans, smoked paprika, chili powder, cinnamon, and salt. Remove from heat and let cool slightly, then mix in the shredded cheese.

2. Prepare the peppers and salsa: Broil the poblano peppers and halved onion on a sheet pan under a high broiler setting. Roast until the skins are blackened and blistered on all sides, about 5 minutes per side. Transfer the hot peppers and onion to a clean kitchen towel, cover loosely, and let steam for about 5 to 10 minutes to loosen the skins. Peel off the skins gently; it’s okay if some skin remains.

3. Blend the peeled roasted onion, tomatoes, serrano chilies, garlic, and cilantro to your desired salsa consistency. Heat 1 tablespoon of oil in a skillet, add the blended salsa, season with salt and pepper, and simmer until the salsa thickens and changes color from light pink to a rich red-orange.

4. Slice each poblano pepper lengthwise and carefully remove membranes and seeds. Stuff each pepper with the filling, then seal the opening with toothpicks to keep the filling secure during frying.

5. Prepare the batter and fry: Heat the frying oil to 375°F (190°C). Separate the eggs; beat the egg whites until soft peaks form, then beat in yolks one at a time until the batter is light, fluffy, and smooth.

6. Dredge each stuffed pepper in flour, tapping off excess, then dip into the egg batter, coating all sides. Fry the peppers carefully in hot oil without overcrowding the pan (1 or 2 at a time), turning gently, until golden brown and crispy on all sides—about 3 to 5 minutes per side. Drain on paper towels.

7. Serve the chile rellenos immediately, accompanied by the prepared salsa roja and optionally garnished with fresh cilantro or crumbled cheese.