Thinly slice the onions and garlic.
Cut the cherry tomatoes in half; chop the herbs.
Drain then rinse the lentils with water, then drain again.
Cut the cheese into 6-8 slices.
Heat 1 Tbsp of oil in a pan, then soften the onion. Add the garlic, stir for one minute, then add the tomatoes and cook for 3-4 minutes.
When the tomatoes begin to soften, stir in the lentils and balsamic vinegar, season with salt and pepper and heat through.
Meanwhile, heat a griddle pan and brush the cheese slices with oil, then fry them for 1-2 minutes on each sides.
Add the chopped herbs and the remaining oil to the lentils, together with the lemon juice. Toss well.
Serve warm with the griddled halloumi on top.