Toast the fonio for about 2-3 minutes. Add the water and salt. Bring to a boil, and simmer for 2 minutes. Turn off the heat and cover the pot for about 5 minutes. Fluff with a fork and let it cool.
Sautee the mushrooms with olive oil, salt, and pepper until all the liquid evaporates and the mushrooms become fragrant (it could take about 20 minutes). Take off heat and put aside to cool.
Chop all the greens (scallions, garlic or chives, parsley, and dill) in a food processor. Add the cooled fonio, cooled mushrooms, and the rest of the ingredients, including the greens, to a big bowl
Mix all the ingredients well and until you get a thick paste.
Preheat the oven to 350F/180C and line a medium loaf pan with parchment paper. Fill the loaf pan with the mixture, and bake for 55 minutes or until golden brown and settled.
Let it cool in the pan for about 30-40 minutes, then gently remove it on a cutting board. You can slice it while still warm or serve it cold. It can also be stored in the refrigerator.