1/2 cup all-purpose flour or gluten-free all-purpose flour
1 tsp. dried basil
1 tsp. sea salt
1 tsp. freshly ground black pepper
3 tbsp. canola oil
Fill a large pot with enough water to reach the bottom of a steamer basket. Using a knife or your hands, break tempeh into four pieces and place in basket. Cover and steam for 20 minutes. Check pot occasionally and add more water if necessary. Steaming tempeh will remove bitterness (if using brown rice, skip this step).
Meanwhile, heat olive oil in a large non-stick skillet over medium-high heat. Saute onions until soft and lightly browned. Add garlic and cook a few more minutes. Transfer to a food processor. Keep skillet for later use.
Add steamed tempeh (or rice), lentils, walnuts, flour, basil, salt, and pepper to the onions in the food processor. Pulse until walnut pieces are very fine and the mixture comes together. If necessary, transfer mixture to a large bowl and mix with your hands. Adjust seasoning to taste. Form mixture into eight burger patties with the palms of your hands.
Heat canola oil in skillet over medium-high heat. Pan-fry patties in batches, adding more oil as needed. Flip and cook until nicely browned on both sides. Remove and drain on paper towels.