Heat oil in a high-sided sauté pan over medium heat.
2 tablespoon neutral oil
Add onions and salt, reduce the heat to medium-low, and cook until deeply golden and jammy, about 25 minutes.
1 large onion, 1 teaspoon salt
Add a splash of water as needed to prevent sticking.
Add garlic and ginger; cook until fragrant, about one minute.
4 garlic clove, 1 tablespoon fresh ginger
Stir in the apple, carrot, potato, and bay leaf.
1 medium apple, 2 medium carrot, 1 medium Yukon gold potato, 1 bay leaf
Add curry powder and dry spices, and bloom briefly.
1½ tablespoon curry powder, 1 teaspoon ground cumin, 1 teaspoon ground coriander, ½ teaspoon turmeric, ¼ teaspoon fenugreek, black pepper
Pour in four cup (one liter) of the strained stock and simmer for 20-30 minutes, until vegetables are tender.
Remove the bay leaf and a few carrots and potato pieces, reserving the veggies for later.
Blend the curry until completely smooth using an immersion blender or a stand blender. Set aside.
In a separate pan, melt butter over medium heat.
3 tablespoon butter
Add flour and cook until blonde-to-light brown and nutty.
3 tablespoon all-purpose flour
Stir in curry powder and cook for 30 seconds.
1 tablespoon curry powder
Gently pour the curry into the roux, whisking constantly to combine. Continue to whisk until the curry has slightly thickened. Add the remaining stock, whisking to combine.
Stir in Worcestershire sauce, soy sauce, ketchup, and honey.
1 tablespoon Worcestershire sauce, 1 tablespoon soy sauce, 1 tablespoon ketchup, 1-2 teaspoon honey
Lightly simmer the curry for ten minutes until glossy and cohesive. Season with salt and pepper to taste.
Optional: Add one small square (5 gram) of dark chocolate for extra depth.
optional: 1 small square (5 gram) dark chocolate