Pupusas - cooking recipe

Ingredients

Salsa Roja:
4 cups plain tomato sauce
1 cup water
4 bunches fresh cilantro, chopped
1 green bell pepper, seeded and chopped
1 onion, chopped
2 cloves garlic, crushed
1 cube chicken bouillon
salt to taste
Curtido:
1/2 head cabbage, shredded
1 large carrot, peeled and grated
1/2 cup white vinegar
3 scallions, minced
2 tablespoons dried oregano
1 pinch crushed red pepper flakes
Chicharron:
1 (12 ounce) package bacon, or to taste
4 tomatoes, halved, or more to taste
1 green bell pepper, seeded and quartered
1 cup grated Monterey Jack cheese
2 cloves garlic, minced (optional)
salt to taste
4 cups masa harina, or more to taste
2 cups water, or as needed
1/2 cup vegetable oil for frying

Preparation

Combine tomato sauce, water, cilantro, green bell pepper, onion, crushed garlic, bouillon cube, and salt in a saucepan over medium-low heat. Cook and stir until vegetables are soft, about 20 minutes. Let salsa roja cool for 10 minutes.
Fill a blender halfway with the salsa roja. Cover and hold lid down with a potholder; pulse a few times before leaving on to blend. Pour into a bowl. Repeat with remaining salsa roja. Return to saucepan and simmer for 10 minutes more stirring occasionally. Allow to cool completely, about 1 hour, and refrigerate.
Place cabbage and carrots in a large bowl. Add 4 cups boiling water and let stand for 5 minutes. Drain well. Mix in vinegar, scallions, oregano, and red pepper flakes. Chill curtido until serving.
Place bacon in a large skillet and cook over medium-high heat, turning occasionally, until almost fully cooked and not yet crispy, 5 to 7 minutes. Transfer bacon and grease (if desired) to a food processor. Add tomatoes, quartered green bell pepper, Monterey Jack cheese, and minced garlic. Puree and season the chicharron with salt.
Mix masa harina and 1/2 cup water together in a bowl by hand. Add the remaining water slowly, about 2 tablespoons at a time, mixing well after each addition, until dough is moist but still firm. Cover with a wet towel.
Heat 1/2 cup oil a large skillet over medium-high heat.
Take a golf ball-sized piece of dough and roll into a ball in your hands. Make a hole in the dough ball with your thumb; put a small amount of chicharron inside the hole, close it up, and flatten the ball with your hands into a thick tortilla shape. Place pupusa in the skillet and fry until golden brown, about 2 minutes per side. Repeat with the remaining dough and chicharron.
Serve each pupusa topped with 2 tablespoons of curtido and 1 tablespoon of salsa roja.