Set a large Dutch oven or soup pot on the stove over medium heat.

Add the olive oil to the pot and heat it for about 30 seconds, until it looks loose and glossy.

Add the chopped onion and carrots to the pot. Cook, stirring often, for 6 to 8 minutes, until the onion is soft and the carrots start to look tender.

Add the garlic and grated ginger to the pot. Cook for 1 minute, stirring, until both smell fragrant.

Sprinkle the cumin, smoked paprika, and red pepper flakes, if using, into the pot. Stir for about 30 seconds so the spices warm through.

Add the tomato paste to the pot. Stir it into the vegetables and cook for 1 to 2 minutes, until it darkens slightly and coats the bottom of the pot.

Add the rinsed lentils to the pot and stir for about 30 seconds so they are coated in the tomato mixture.

Pour the crushed tomatoes and vegetable broth into the pot. Add the kosher salt and black pepper.

Turn the heat to high and bring the stew to a boil. Stir once to make sure nothing is sticking to the bottom of the pot.

Lower the heat to maintain a gentle simmer. Partly cover the pot and cook for 25 to 30 minutes, stirring once or twice, until the lentils are tender but still holding their shape.

Put the peanut butter into a small bowl.

Ladle about 1/2 cup of the hot broth from the pot into the bowl with the peanut butter. Whisk until the mixture is smooth and pourable.