My husband is a 'vegetarian' who eats fish, eggs * dairy, so I have learned over the years to be versatile & eat more veggie food than meat now. If you want a really filling meal, you can use pasta (all/any type) and make cheesey spaghetti/pasta or you can make a creamy sauce and mix with fish or shellfish. Pasta is often the easy way out.
1 600g pasta; 350g Cheese (I prefer to use cheshire 'cos it crumbles but any will do if not too mild)
2 tins of chopped tomatoes ( If not chopped drain the liquid into the pasta then cut up whilst still in the tin) salt & pepper to your taste; a good amount of oregano or mixed herbs (to your taste); 1 clove of garlic
tomato puree (about one third of a tube); a little worcester sauce (optional), depends if you like it spicy.
Boil enough water to cook the pasta, add salt and pepper and add the pasta to boiling water and bring back to the boil. Whilst it is cooking, grate the cheese, open cans of tomatoes, peel & crush the garlic. Just before the pasta is cooked drain away some of the water as you will now add the tins of chopped tomatoes and the liquid from the tins. Add the tomato puree and stir in well, stir in the herbs, garlic and grated cheese. need a fairly high heat for the cheese to melt, then add the worcester sauce if using it. Serve in bowls and sprinkle the top with a few herbs. All you need to go with it is a glass of wine. Everything in one pot.
Tons of recipes on the internet to see you through.