Preheat the Oven: Preheat your oven to 500°F (260°C). Line a baking sheet with aluminum foil.
Prepare the Tomatillos: Set aside 4 raw tomatillos. Place the remaining halved tomatillos and the roma tomato cut-side down on the baking sheet. Roast in the oven until they begin to toast, about 20 minutes.
Blend the Salsa: In a food processor, combine the roasted tomatillos and tomatoes, the raw tomatillos, jalapeños (start with a half if you're unsure of the spice level; see Note 1), red onion, garlic, cilantro, cumin, and oregano. Pulse until the mixture is mostly smooth but still has some texture (see Note 2).
Adjust Spice Level: Taste the salsa and add more jalapeños and/or seeds according to your preferred spice level. Keep in mind that salsa will taste spicier when warm and on its own, but it will be milder when chilled and served with food.
Season: Add the lemon and lime juices, then season to taste with salt and pepper (about 1 teaspoon salt and ½ teaspoon pepper is recommended).
Serve and Enjoy: This recipe yields about 6 cups of delicious salsa!