Preheat oven to 350.
Add figs to a bowl and cover with hot tap water. Set aside to soak, at least 10 minutes.
Heat a stock pot to medium-high heat and add oil. When oil moves quickly around the pot, add sweet potato, celery and onion. Cook, stirring every few minutes, until softened and translucent, approximately 10 minutes. You can add small splashes of water to prevent burning/sticking if you like.
Turn heat to low and add garlic, pepper and salt, stirring constantly for 30 seconds. Add lentils and 2 ½ cups water or low-sodium vegetable broth and stir to incorporate all ingredients together. Bring to a rapid simmer (a little less than a boil) and simmer for 15-18 minutes, until all of the water is absorbed.
While lentils are cooking, add walnuts to a baking sheet and roast for 12 minutes, then set aside to cool. Also, while lentils are cooking, drain figs and pull off any stems. Add to a blender, along with balsamic, ketchup, dijon and tamari. Blend until as smooth as possible--it’s ok if there are some little fig pieces.
Line a loaf tin with non-stick parchment paper.
Add oats and 6 tablespoons of the balsamic/fig glaze to a large mixing bowl. Stir to incorporate.
When lentils are finished cooking, add to the mixing bowl with oats. Chop cooled walnuts and add to the mixing bowl as well. Stir mixture together to evenly incorporate, then add to your lined loaf tin. Press to pack it into the tin, smoothing out the surface.
Bake for 35 minutes, then spread a layer of fig/balsamic glaze on top and bake another 15 minutes. Save remaining glaze to serve with loaf. Cool 30 minutes in the tin, then remove and cool another 20 minutes before slicing.
Loaf will keep tightly sealed in the refrigerator up to 4 days.