Rinse the red lentils thoroughly in cold water until the water runs clear, then drain and set aside.
Heat oil in a wide pan over medium heat until it shimmers and starts to ripple.
Add chopped onion and sauté, stirring frequently, until it becomes translucent and begins to turn golden around the edges, about 5 minutes. The kitchen will fill with a sweet aroma.
Stir in minced garlic and grated ginger, cooking for about 30 seconds until fragrant and fragrant steam rises.
Add turmeric, cumin, and smoked paprika to the pan, stirring constantly to toast the spices and release their essential oils, about 1 minute. You’ll notice the spices darken slightly and the aroma intensifies.
Pour in water or broth, bringing it to a gentle boil. Once bubbling, add the rinsed lentils and stir to combine.
Reduce the heat to low and let the mixture simmer uncovered, stirring occasionally, for 15-20 minutes. The lentils will soften and start to break apart, creating a thick, velvety sauce. If it gets too thick, add a splash of hot water and stir.
Taste the curry and add salt as needed. Squeeze in fresh lemon juice to brighten the flavors and stir well.
Remove from heat, garnish with chopped cilantro, and let sit for a few minutes to allow flavors to meld.
Serve the warm, creamy lentil curry over rice or with flatbread, enjoying its comforting aroma and vibrant color.