Heat a large, straight-walled saucepan over medium heat. Add the olive oil and, once hot, the garlic and cumin seeds. Cook, stirring, until fragrant (1 to 2 minutes).

Pour in the vegetable broth and deglaze the pan, then add the lentils. Bring to a boil, then reduce the heat to maintain a rapid simmer. Cook until the lentils are fairly tender and have absorbed most of the liquid, adding more broth if necessary (25 to 30 minutes).

Turn the heat to low, add the tahini and soy sauce, and stir into the lentils to combine. Season with salt, if needed, and black pepper.

Add the water to a medium saucepan. Add salt, farro, bay leaves, and garlic, then reduce to a simmer and cook until somewhat tender but still slightly chewy (20 to 30 minutes). Once done, drain the farro and discard the bay leaves and garlic cloves. Optionally spread the farro on a sheet pan to cool to avoid the texture becoming mushy.

Combine the lentils and farro in a bowl. Top with pickled red onions and hummus.