Peel and chop the parsnips and cook in boiling salted water until tender.
Whilst the parsnips are cooking, dry fry coriander seeds, fenugreek seeds and mustard seeds until the mustard seeds pop. Grind the seeds to a powder.
For the skordalia, mash the drained parsnips with a fork or potato ricer adding the olive oil, 2 finely chopped cloves of garlic and saffron infused milk. Add salt to taste. Keep the mixture warm.
Add the vegetable oil to a frying pan with the remaining chopped garlic and heat gently. Add the mushrooms and fry gently for a few minutes. Add the toasted ground seeds and chilli powder together with a few tablespoons of water.
Place a lid over the pan and cook gently until the mushrooms are tender.
To serve, arrange the mushrooms and the pan juice over the parsnip skordalia and sprinkle with white sesame seeds.