Creamy beef curry

Name: Creamy beef curry
Prep time: 10 min
Cook time: 1 h 15 min
Total time: 1 h 15 min
Yield: 4 portions
Ingredients: 2 garlic cloves; 1 cm piece fresh ginger; 1 - 2 fresh red chillies; 2 brown onions; 45 g salted butter; 20 g curry powder; 2 tsp ground turmeric; 2 tsp yellow mustard seeds; 1000 g beef chuck steak; 400 g canned crushed tomatoes; 20 g raw sugar; 1 tbsp white vinegar; 15 g Meat stock paste; 150 g pouring (whipping) cream; 1 - 2 pinches sea salt; 1 - 2 pinches ground black pepper; fresh coriander leaves; lemon