Choose a new cookbook worth up to £28 when you subscribe to our magazine.
Finely grate the garlic and put in a bowl. Boil the lentils for 25 mins, and put the asparagus in a steamer over them for the last 5 mins until just tender.
Meanwhile, put the onions, cranberries, oil and vinegar in the bowl with the garlic and stir well. When the lentils are ready, drain and toss them into the dressing with the tomatoes. Tip into plastic containers (for a packed lunch), or onto plates, then top with the asparagus and crumble over the feta. Drizzle with a little extra oil, if you like.