Heat the olive oil in a large skillet over medium heat. Add the chopped onion, carrot, and celery. Sauté for 5–7 minutes, until softened and translucent.
Add the minced garlic and cook for another 1–2 minutes, stirring frequently, until fragrant.
Stir in the tomato paste, crushed tomatoes, dried oregano, and dried basil. Cook for 2–3 minutes to deepen the flavor.
Add the rinsed lentils and vegetable broth. Stir to combine, then bring to a boil.
Reduce heat to low and simmer uncovered for 25–30 minutes, stirring occasionally, until the lentils are tender and the sauce thickens.
Season with salt, black pepper, and soy sauce (if using). Adjust to taste.