Place lentils in a small pot, cover with at least 3" of cold water and bring to a boil over medium high heat. Lower the heat until the lentils simmer gently, and then cook 10 to 15 minutes, until very tender, but still holding their shape. Drain the lentils into a fine sieve, and let them drain and cool there to room temperature.
Set an oven rack in the middle of the oven; preheat the oven to 425˚F. Line a large baking sheet with parchment paper.
Place the flours, baking soda, baking powder and salt in a bowl and whisk well to combine. Using your fingers, two forks or a pastry cutter, work the butter into the flour mixture until thoroughly distributed. Mix the cheese, green onion and thyme into the flour mixture.
Push on the lentils and squeeze any excess moisture left in them out through the sieve. Set lentils in a large bowl, or bowl of your stand mixer fitted with paddle attachment, and mix in the buttermilk. Add the flour mixture and mix until a loose dough forms.
Lightly dust a clean work surface and your hands with flour. Turn the dough onto the surface and knead and shape it into a round, squat loaf about 6" wide.
Place the shaped dough on the prepared baking sheet. Using a knife lightly dusted with flour, cut a shallow X into the centre of the loaf.
Bake the bread for 35 to 40 minutes, or until the loaf springs back when gently touched in the centre. Cool bread to room temperature on a baking rack, and then serve.
Note: Dried red lentils are sold in bags in our canned soup aisle and in our Bulk Foods Department. They are small and split, which means you don’t have to soak them before cooking. Garbanzo and Fava Bean Flour is sold in our baking supply aisle. This flour is also used in our Gluten-free Banana Pecan Muffins recipe.