I start by heating the olive oil in my Dutch oven over medium heat, then adding the chopped onion and carrots. I let them cook for about eight minutes, stirring occasionally, until they turn soft and slightly golden. This step builds the flavor base for everything that follows, so I never rush it.
Next, I stir in the red curry paste, minced garlic, grated ginger, and pumpkin pie spice. I cook this mixture for about two minutes, just until it smells fragrant and toasty. This quick step wakes up the spices and makes the whole kitchen smell incredible.
I pour in the rinsed red lentils, pumpkin puree, vegetable broth, water, and salt, then give everything a good stir. I bring the pot to a gentle boil, then partially cover it and drop the heat to medium-low so it doesn't scorch on the bottom.
I let the soup simmer for about 30 minutes, stirring every so often, until the lentils turn completely soft and the mixture thickens naturally. You'll notice the texture change from watery to velvety right before your eyes, which is my favorite part of this recipe.
Once the lentils are tender, I stir in the coconut milk, then use my immersion blender to puree about half the soup directly in the pot. I like leaving some texture instead of blending it completely smooth, since it makes the soup feel heartier.
Finally, I squeeze in the fresh lime juice and give it one last taste for seasoning. I ladle it into bowls right away while it's steaming hot, and add my favorite toppings before bringing it to the table.