Combine vegetable broth and rinsed brown lentils in a saucepan.

Bring to a boil, then reduce heat and simmer for 20-30 minutes, or until lentils are soft and broth is absorbed.

Drain any excess broth, if necessary.

Slightly mash the lentils.

Transfer the mashed lentils to a large mixing bowl.

Preheat oven to 350 degrees F (175 degrees C).

Grease a loaf pan.

Add quick-cooking oats, shredded Cheddar cheese, panko bread crumbs, beaten eggs, finely chopped onion, ketchup, crushed garlic cloves, dried parsley, Worcestershire sauce, dried basil, red pepper flakes, salt, and black pepper to the bowl with the lentils.

Mix all ingredients well to combine.

Transfer the mixture to the prepared loaf pan.

Bake in the preheated oven for 35-45 minutes, or until the loaf starts to brown.

Let the meatloaf sit for 10 minutes before serving.

Loosen the sides using a spatula before slicing and serving.