Vegetable Samosas

Name: Vegetable Samosas
Ingredients: * 85 g butter; * 180 ml boiling water; * 350 g plain flour; * 1 pinch of salt; for the filling:; * 350 g pumpkin or sweet potato, peeled and chopped into cube; * 3 large potato, peeled and chopped into cube; * 2 tbsp olive oil; * 1 medium onion, finely chopped; * 2 tsp mustard seed; * 2 tsp cumin seed; * 1 tsp cardamom powder; * 1 tsp garam masala; * 1/2 tsp turmeric; * salt and pepper, to taste; * 3 large handful pea, podded; * 1 small handful of coriander, chopped