- In a large saucepan, heat olive oil over medium heat. Add onions and carrots; cook, stirring often, until softened, 4 to 6 minutes. Add garlic and pepper flakes; cook, stirring, 30 to 60 seconds. Add lentils and thyme; stir to coat. Add broth and bring to a simmer. Reduce heat to low, cover and simmer, 25 minutes.
- Alternatively, make lentils in a rice cooker or instant pot.
- Preheat the oven to 350°F.
- Stir 6 tablespoons melted butter and tomato paste into lentils. Transfer mixture to a deep 3-quart casserole dish. Stir in pasta, tomatoes. Season with salt and pepper to taste. Pour in 1 cup boiling water (or more broth).
- Cover with an oven-proof lid or foil and bake until lentils and orzo are almost tender, about 25 minutes. Uncover and stir to redistribute ingredients. (Casserole can be made ahead to this point. Cover and refrigerate up to 2 days. Reheat on stovetop, adding enough water to achieve stew-like consistency. Return to the casserole dish.)
- In a small bowl, mix together bread crumbs, parsley and remaining 2 tablespoons of melted butter. Sprinkle over the casserole. Bake uncovered until bubbly and top is crusty, 15 to 20 minutes more. Serve hot.
Source: https://www.vegetariantimes.com/recipes/lentil-orzo-casserole