Caldo de res (Mexican beef broth with vegetables)

Ingredients

• 800 g beef shank, ribs, or chuck, bone-in
• 400 g marrow bones, cut into 5 cm sections, one per person
• 2 ears of corn, husked, cut into thirds
• 2 chayote, peeled, quartered
• 2 carrots, peeled, cut into large chunks
• 2 potatoes, peeled, cut into large chunks
• ¼ head of cabbage, cut into thick wedges
• 1 white onion, halved and charred on a dry comal
• 4 garlic cloves, charred on a dry comal
• 10 g dried oregano, to serve alongside
• 2 limes, quartered, to serve alongside
• 1 tsp fine salt, plus more to taste

Method

1. 1
   Place the bone-in beef and marrow bones in a large pot. Cover with cold water — at least 3 litres. Set over medium-low heat and bring slowly to a bare simmer. Rapid boiling from the start emulsifies fat and protein into a cloudy broth; the surface should tremble, not roll.
2. 2
   As the liquid approaches a simmer, grey foam will rise to the surface. Skim it away continuously for the first 30 minutes, removing the proteins that cloud the broth. The broth is ready to proceed when the foam has subsided and the liquid runs clear amber at the surface.
3. 3
   Add the charred onion halves and charred garlic cloves — the Mexican aromatic base — along with salt. Maintain a gentle, steady simmer. The beef must cook until the meat yields at the bone and pulls away without resistance; this is where the dish lives or dies. Gelatin from the bone collagen and richness from the marrow are what give the broth its body — boneless beef cannot substitute. Allow approximately 1½ to 2 hours, testing by pressing the meat; it should give completely under light pressure.
4. 4
   Add the corn pieces to the broth. They require approximately 40 minutes and set the timing for all subsequent vegetables. The broth will take on a faint sweetness.
5. 5
   After 20 minutes of the corn's cooking time, add the chayote, carrot, and potato. These harder vegetables need approximately 20 minutes alongside the corn. They are done when a knife tip meets no resistance at their centre.
6. 6
   Add the cabbage wedges in the final 10 minutes. They are done when just tender but still holding their shape — not collapsed. Taste the broth and adjust salt.
7. 7
   Ladle the broth into deep bowls, distributing meat, marrow bones, corn, and vegetables equally. Serve with quartered limes, dried oregano, and salsa borracha alongside. The marrow may be scooped from the bone and spread on tortillas.