heat olive oil in a large pan and add in onions, cook for 2-3 minutes. Reduce heat and add in red bell pepper, cook for 2 minutes. Add in garlic, chili powder, cumin, turmeric and chili flakes and cook for 1-2 minutes, spices will begin to give off an aroma and stick to the pan - stir constantly.
Add in a bit of the spinach water to deglaze the pan - a bit of a sauce will start to develop. Keep the spinach water handy and continue to add in to ensure that the flavors are mixed together. You'll want the water to have all evaporated by the time you're finished so don't put in too much - you won't likely use it all.
Add in the spinach, tahini and crumbled tofu and mix well with the rest of the ingredients. Add in additional spinach water if you need it to ensure everything is coated. Continue to cook until everything is cooked through.
Season with salt and pepper to taste. *note - I used salt throughout the cooking process rather than waiting until the end but you do whatever you are most comfortable with. The flavors will be quite strong right after you add the spices so the true test of how much salt is needed will come after you've added in the tofu and spinach.
Top with cilantro and serve with salsa if desired!