Mango Chili Meatballs

Preheat the oven to 425 degrees F, ensuring a rack is positioned in the top 1/3 of the oven, about 8 inches under the broiler.
Place the tallow or butter into a large skillet over medium heat. Once the oil is hot, add in the onion. Season with a pinch of salt. Cook, stirring occasionally, until softened & fragrant, about 5 minutes. Add the garlic & cook another minute, or until fragrant. Remove from the skillet and place into a large bowl.
Once the onion mixture is cool enough to touch, add the ground beef, ground pork, eggs, cheese, diced mushrooms, and LMNT. Use your hands to combine well. Form the mixture into meatballs slightly larger than the size of a golf ball, rolling just until smooth – take care to avoid pressing the meatballs together too compactly. For quickness & ease, I use a 2-inch spring-loaded ice cream scoop. Place the meatballs on a large rimmed baking sheet.
Bake in the oven for 10 minutes. After 10 minutes, turn oven to broil and cook another 5 to 8 minutes or until you have a nice brown crust on the outside.
While the meatballs cook, place the salsa or pico de gallo into a large skillet and heat over medium heat.
Once the meatballs are cooked through, place them to the skillet with the sauce. Simmer for 10 minutes. If desired, top with crumbled cotija or Mexican cheese and cilantro leaves. Serve warm.