Put the lentils and vegetable broth in a saucepan. Bring to a boil, then lower the heat and simmer until the lentils are tender but still hold their shape, about 20 to 25 minutes. Drain any remaining broth and let the lentils cool slightly.

Heat the olive oil in a skillet over medium heat. Add the onion and carrot and cook until softened, about 5 minutes. Stir in the zucchini and garlic and cook for 2 minutes more. Remove the skillet from the heat.

In a large bowl, mash about half of the cooked lentils. Add the remaining lentils, cooked vegetables, oats, egg, 1 tablespoon of the tomato paste, smoked paprika, thyme, ½ teaspoon of the salt, black pepper, and soy sauce. Mix until combined, then let the mixture stand for 10 minutes so the oats can absorb moisture.

While the mixture rests, stir the maple syrup, apple cider vinegar, and remaining 1 tablespoon tomato paste together in a small bowl. Set the glaze aside.

Preheat a smoker to 250°F. Shape the lentil mixture into four small loaves and place them in a shallow, smoker-safe baking dish, leaving space between each loaf.

In a separate bowl, combine the white beans, crushed tomatoes, water, onion powder, and remaining ½ teaspoon salt. Pour the bean mixture around the loaves in the baking dish.

Smoke uncovered until the loaves are firm and the bean sauce is bubbling, about 1½ to 2 hours. Brush the maple-tomato glaze over the loaves during the final 20 minutes. Let the dish rest for 5 minutes before serving.