Melissa Hemsley's simple Brussel sprout fritters

Name: Melissa Hemsley's simple Brussel sprout fritters
Yield: 15 fritters
Ingredients: 150g cooked brussel sprouts (about 2 handfuls); 250g cooked root veg eg sweet potatoes, carrots, parsnips, swede, potatoes (about 2 large handfuls); 1 small onion finely chopped; 1 medium egg; 2 - 3 tbsp flour, I used chickpea flour; 2 - 3 tbs ghee, butter, coconut oil, leftover chicken/beef/duck fat (from christmas) for frying; Sea salt & pepper (go easy if you've already seasoned your veg from the main meal); A fried or poached egg; Halloumi, mushrooms, leftover cold cuts