Boil the beef tendon in a pot with enough water to cover it. Simmer for 10 minutes, then drain and rinse off excess fat and scum.

In a clean pot, add the beef tendon, celery leaves, and enough water to cover. Simmer for 30 minutes, then separate the broth and beef tendon. Cut the beef tendon into bite-sized pieces.

Prepare the vegetables: finely chop the onion and garlic, slice the carrot into 5mm rounds, divide the broccoli into florets, and trim the mushroom stems.

Heat olive oil in a pot, sauté garlic until fragrant, then add onion and cook until softened. Add the beef tendon and stir until coated with oil.

Add the seasoning ingredients (canned tomatoes, salt, pepper, red wine, and broth). Simmer on low heat for 30 minutes, stirring occasionally.

Microwave the carrot and broccoli with a tablespoon of water for 2 minutes, then drain.

Heat olive oil in a pan, sauté mushrooms, carrots, and broccoli until tender. Season with salt and pepper.