reheat the oven to 200°C (400°F).
Cut the beets, carrots and red onion into more or less equal-sized chunks. Slice the green beans in two. Drizzle the vegetables with 2 teaspoons of oil and toss. Arrange on a baking sheet. I like to put the beets in a separate dish just in case they need a couple more minutes to roast. Roast the vegetables for 30-40 minutes or until tender.
Meanwhile prepare the barley. Place the barley and 1 ½ cups (355 ml) of water in a small pan and bring to a boil. Reduce the heat to low and cover. Cook for 30 minutes or until tender. If there is any water remaining in the pot simply drain it off. Allow the barley to cool slightly then mix it with the sprouted lentils and ½ teaspoon of salt.
Once the beets are roasted and cooled enough to touch, prepare the sauce. Combine 120 grams (4 oz) of the beets (about ½ a cup of beets) with the remaining ½ cup (120 ml) of water, ½ teaspoon of salt, the tahini, vinegar and garlic in a blender or food processor. Process until smooth.
Make the bowls by dividing the barley-lentil mix between two bowls and topping with the roasted vegetables, sliced radishes, lemon slices and a few grinds of pepper. Serve the beet sauce on the side.