Tip the lentils into a small saucepan, cover with water and bring to the boil. Turn the heat down to medium and cook for 12 minutes, or until tender. Drain, return to the pan and season lightly with sea salt, black pepper and a drizzle of olive oil. Meanwhile, place the porcini into a small bowl, just cover with boiling water and leave to rehydrate. Peel the onion and garlic, trim the celery and finely chop together. Pick and finely chop the rosemary leaves. Heat a splash of olive oil in a medium pan over a medium-low heat, add the chopped veg, bay and rosemary, then cook gently with a lid on for 10 minutes, or until softened, stirring occasionally. Turn the heat up to medium-high, pour in the red wine (if using), then leave to bubble and cook away. Finely chop the porcini and add to the pan, along with the soaking water, leaving any gritty bits behind. Tip in the tomatoes, breaking them up with a spoon as you go, then add half a tin’s worth of water. Bring to the boil, then reduce to a medium-low heat and cook for 10 minutes, adding the lentils as soon as they’re drained and ready. Cook the spaghetti in a pan of boiling salted water for 8 to 10 minutes, or until al dente, which means that it should be soft enough to eat, but still have a bit of bite and firmness to it. Pick the thyme leaves into a bowl, add the breadcrumbs and ½ a tablespoon of extra virgin olive oil, then toss to coat. Toast in a dry frying pan over a medium heat until lightly golden, stirring regularly. Remove the bay leaf and mash the sauce gently with a potato masher, then season to taste with salt and pepper. Scoop out and reserve a cupful of the pasta cooking water, then drain the spaghetti and tip back into the pan. Add the sauce and mix together, loosening with splashes of cooking water, if needed. Divide between your bowls, sprinkle with the herby breadcrumbs, grate over the cheese and serve.