Polenta with chicken liver sauce, spring greens

Polenta, quick cook, only 5 minutes stirring; bland base for a chicken liver sauce: 

Soften a large chopped onion in a little olive oil. When soft, add 2 chopped garlic cloves and cook for another 2-3 minutes. Remove from pan. In the same pan quickly cook thinly sliced mushrooms. When mushrooms are cooked put onions back into the pan. Add enough water to make a sauce, a couple of tablespoons of tomato puree, the juice of half a lemon,and a good shake of soy sauce. Let simmer. Meanwhile quickly brown chopped chicken livers. Mix livers into sauce and serve on top of the polenta.