In a large saucepan, heat 1 tbsp of oil over medium heat. Add the onion and garlic and stir to combine. Saute for 5-6 min, until the onion.
Stir in the mushrooms and raise heat to medium-high. Cook for about 5 to 10 minutes, until much of the liquid released by the mushrooms has cooked off.
Add the basil, whole peeled tomatoes and juices, tomato paste, salt, oregano and thyme. Stir to combine. Add the red pepper flakes, the chia seeds, and lentils then stir to combine.
Reduce the heat to medium. Simmer the sauce, stirring every so often, for 15 to 20 minutes.