Nilagang baboy: boiled pork with vegetables

Ingredients

• pork bone marrow (optional)
• 150 g pork (spare ribs or your choice cut)
• 1 whole onion, chopped in quarter
• 1 tablespoon whole peppercorns
• 2 pieces potatoes, chopped in quater
• bunch of bok choi/chinese cabbage/pechay
• handful of spring onions, chopped
• salt
• pork broth cubes (optional)
• 3 to 5 cups water or rice water