Prepare all your ingredients: chop the bell peppers into bite-sized pieces, dice or chop the tomatoes, thinly slice the onion, and mince the garlic and grate the ginger. Keep everything within arm’s reach.
Heat a large wok or skillet over medium-high heat, then add the vegetable oil. When the oil shimmers and you hear a faint crackle, add the sliced onions. Stir-fry until they turn translucent and slightly golden, about 3-4 minutes, releasing a sweet aroma.
Add the minced garlic and grated ginger to the pan. Cook, stirring constantly, until fragrant—about 1 minute—until you see a burst of aroma and the mixture slightly thickens.
Sprinkle in the turmeric, cumin powder, and chili powder. Toast the spices in the oil for about 30 seconds, stirring constantly, until they darken slightly and release a smoky aroma.
Add the chopped bell peppers and tomatoes to the pan. Stir everything together so the vegetables are coated with the spices. Cook for about 8-10 minutes, stirring occasionally, until the peppers are tender and slightly charred, and the sauce has thickened to a glossy consistency.
Taste the dish and adjust seasoning if needed—adding more chili or salt to suit your preference. Turn off the heat and stir in chopped fresh cilantro for a bright, herbal finish.
Let the jalfrezi rest for a minute or two to allow flavors to meld. Then, serve hot, accompanied by rice or flatbread, and enjoy the vibrant, spicy flavors.