Prepare the tofu and onions by cutting the tofu into cubes and letting them drain on paper towels to remove moisture. Soak the sliced onions in cold water for five minutes to soften their bite, then drain them well.

Build the aromatic base by heating oil in a large pot over medium heat. Sauté the diced onions until they are soft and translucent, which should take about four minutes. Stir in the garlic, ginger, and both fresh and dried chiles, cooking until the onions are completely soft and just starting to turn golden.

Add the squash, turmeric, paprika, salt, and tamarind salt to the pot, stirring to coat the vegetables in the spices. Pour in the water and bring the mixture to a boil.

Simmer the stew by lowering the heat and cooking for about 20 minutes. You'll know it's ready when the pumpkin is tender enough to be easily pierced with a knife.

Finish the dish by gently folding in the tofu and garam masala. Continue to simmer for five more minutes until the sauce thickens and glazes the tofu. For the best flavor, let the stew rest for ten minutes before serving with the prepared garnishes.