Beef soup with jalapeño chiles

Heat the vegetable oil in a large pot or Dutch oven over medium-high heat. Add the beef shank pieces and sear until well browned on all sides.

Add 100 grams of the halved white onion, 15 grams of the whole garlic cloves, the black peppercorns, and 3000 ml of water to the pot with the beef shank. Bring to a boil, then reduce the heat to low, cover, and simmer for 90 minutes, or until the beef shank is tender. Skim any foam that rises to the surface during the first 30 minutes.

While the beef shank simmers, prepare the tomato base: Place the roma tomatoes, the remaining 100 grams of quartered white onion, and the remaining 15 grams of whole garlic cloves on a comal or baking sheet. Roast them over medium heat or under a broiler until softened and slightly charred.