Rinse the cracked wheat and barley and cover generously with cold water in a bowl. Rinse all four pulses and soak them in a separate bowl. Cover and refrigerate for 8 hours. Drain and rinse both mixtures, discarding the soaking water.
Put the drained grains and pulses in the 5 litre saucepan with 900 ml water. Bring to the boil, skim off foam, then simmer gently with the lid slightly ajar for approximately 90 to 120 minutes. Stir every 10 to 15 minutes, more often as the mixture thickens. Add boiling water if needed to keep it loose. Continue until the wheat, barley and chana dal crush easily with no firm centre.
Heat 30 ml oil in the meat pan over a medium heat. Add 150 g sliced onion and cook for about 12 to 15 minutes until golden. Add the Garlic and Ginger Paste and stir for 1 minute. Add the beef and cook, stirring, for about 5 minutes. Add the coriander, cumin, chilli powder, turmeric, pepper, cinnamon, cloves and nutmeg with a splash from the measured beef water; stir for 30 seconds. Add the salt and remaining portion of the 600 ml beef water.
Bring the beef to a simmer, cover and cook gently for about 2 to 2½ hours, stirring periodically. The beef should pull apart readily with a fork; shin may take closer to 3 hours. Add boiling water if the liquid gets low, keeping the meat mostly covered. If the grains finish first, leave them covered off the heat during the remaining meat cooking time.
Heat the remaining 15 ml oil with the ghee in a frying pan over a medium heat. Add the remaining 150 g onion and cook for about 12 to 18 minutes, stirring frequently, until golden. Reduce the heat if the edges brown too quickly. Lift the onions onto a plate with a slotted spoon; retain the flavoured fat in the pan.
Remove the grain pan from the heat and wait for vigorous bubbling to stop. Blend the soft mixture with a submerged stick blender, following its hot food instructions, or mash thoroughly. Lift the tender beef out of its cooking liquid and shred finely with two forks. Keep all the spiced liquid. Avoid blending the meat to a paste.
Add the shredded beef and all its liquid to the blended grain base. Cook over a low heat for 25 to 35 minutes, stirring frequently and pressing against the pan with a sturdy spoon. Scrape the bottom to prevent sticking. Add boiling water in small splashes as needed. Aim for a thick porridge that falls slowly from the spoon, with fine meat strands distributed throughout.
Stir in the garam masala and reserved onion cooking fat. Simmer for 5 minutes, then taste and adjust the salt if needed. Loosen with a little boiling water if it has become stiff. Serve in bowls topped with the fried onions, offering the optional coriander, ginger, chilli, lemon and chaat masala separately. Serve with naan if desired.