Process toasted walnuts and olive oil in a blender or food processor until mixture forms a thick paste. Spoon in the cooked mushroom mixture, and process to desired texture. Pack mixture into well-oiled ramekins or bowl. Cover with plastic wrap, and refrigerate for a few hours or overnight.
Step 1, Place water, lentils, and bouillon cubes in a pot. Cover pot and cook about 30 minutes or until tender. Drain well. Step 2, Heat oil in skillet, saute onion until it becomes translucent. Step 3, In an electric food processor, grind lentils, onions and walnuts until your desired consistency for the pate is reached. Season to taste with salt and pepper. Chill before serving.