Add the lentils, water, garlic, onion, salt, and thyme to a medium pot.
Bring to a simmer and cook for 25-30 minutes or until the lentils are tender but still holding their shape.
Stir in the marinara sauce and warm through.
Serve over rice with optional toppings.
Notes
Store leftovers in an airtight container for 3-5 days in the fridge, or in the freezer in a freezer-safe storage container for up to 3 months. Thaw overnight in the refrigerator and warm to serve.
Add diced zucchini, baby spinach, or baby kale for extra veggies.
Puree the sauce for smaller eaters, or puree and stir into pasta.
Use crushed tomatoes instead of marinara sauce or a less expensive ingredient list. Add more salt to taste and perhaps a little olive oil or butter if needed for flavor.