This spicy curry sauce can be found all over Britain—in chip shops and pubs, and even bottled (or powdered) in markets. The spice can be tailored to the level of heat you want, and the aromatics and toasted spices make a fantastic base for a number of dishes.
The intense, thick sauce is also great to make ahead. It can be kept in the fridge for up to a week (or a few months in the freezer) and once you've made the curry base, you can thin it with stock or water and add it to chopped up leftovers from a roast dinner. This amount of base curry is enough to make a leftover dinner for four people if you add a cup of additional liquid along with your leftovers.
Or, alternately, make up a big batch of salty french fries and top them off with this sauce over for curry fries.
Depending on how you plan to serve it, you can purée the sauce or leave it chunky. To me, the non-puréed sauce is preferable for a meal-sized curry that you're going to simmer with other ingredients (such as roast lamb or chicken and leftover vegetables). If I'm making curry fries and using it as a dipping sauce, then I take the extra step to purée and strain it.
- 2 tablespoons vegetable oil
- 1 medium onion, grated on the large holes of a box grater
- 2 medium cloves garlic, finely chopped (about 2 teaspoons)
- 1-inch piece of ginger, peeled and finely chopped (about 1 tablespoon)
- 1 1/2 teaspoons ground cumin
- 1 teaspoon ground turmeric
- 1 teaspoon paprika
- 1/2 teaspoon ground coriander
- 1/2 teaspoon curry powder (such as Madras)
- Pinch of red pepper flakes
- 1 tablespoon tomato paste
- 1 tablespoon all purpose flour
- 1 1/2 cups water
- 1 tablespoon juice from 1 lemon
- Kosher salt and freshly ground black pepper, to taste
Heat vegetable oil in a medium nonstick skillet over medium-high heat until shimmering. Add onion, garlic, and ginger. Cook, stirring constantly with a spatula, until onions soften, about 5 minutes. Add cumin, turmeric, paprika, coriander, curry powder, and red pepper flakes. Continue to cook until the spices begin to smell toasted, about 6 minutes.
Reduce heat to medium and add tomato paste. Continue to cook, stirring, until tomato paste is evenly incorporated and has begun to reduce, about 3 minutes. Add flour and stir until there are no lumps and no white spots left in the pan. Pour the water and lemon juice into the pan and stir until the mixture begins to thicken. Allow curry sauce to cook until the mixture has reduced to about 1 1/2 cups.
To purée and strain (optional): Transfer curry sauce to a food processor or blender. Process until smooth, then pass through a fine-mesh strainer into a storage container.
Season sauce with salt and pepper to taste, then use to make a variety of delicious curries. Curry sauce can be stored for up to a week in the refrigerator.
Medium nonstick skillet, optional blender or food processor, optional fine-mesh strainer