Toss the small cauliflower pieces in olive oil, smoked paprika, cumin, turmeric and salt ( you can also use really finely chopped stalk too if you like). Spread them onto an oven tray in a single layer (you may have to use two trays).
Roast for up to an hour ( fan forced may be shorter) or until nicely browned and well softened. Set aside about a cup of roasted cauliflower for the finished dip. Pour the rest of the cauliflower, drained beans, garlic, spices, Dijon, tahini, oil and juice into the processor and blend till it is as fine as you can get it, scraping down the sides occasionally.
Now, taste the dip. If you want a dip that is a bit softer add a ¼ cup of water at a time, till you reach the consistency you like. If you like more lemon replace some of the water with that. Add a little salt.
To serve the dip, pour into a nice flat bowl and spread to the sides. Sprinkle with the extra cauliflower, roasted nuts or dukkah and extra smoked paprika and a splash of olive oil if you like!