Tomate Frito From 'Yucatán'

Ingredients (7)

• 2 pounds (1 k) Roma tomatoes, charred and quartered
• 1/2 medium red onion (5 oz/137.5 g), peeled, charred, and quartered
• 1 cup (250 ml) water
• 1 tablespoon (15 g) tomato paste (optional)
• 1 medium chile x'catik (1 1/4 oz/35 g), charred, skin left intact, stem removed, and thinly sliced
• 1/2 cup (112 g) lard, enriched with bacon fat if possible, or extra-virgin olive oil
• 1 teaspoon (6 g) sea salt