Not a purest vegetarian dish, but it's raining so it's more of a bung it in the oven dish.
Tuna Pasta bake.
Tin of Tuna mixed with onion.
Pasta. I only have Penna, half boiled
Tin tomatoes 🍅 chopped.
Mix all ingredients in casserole dishe and bung it in the oven.
Holy **bleep**ing crap...I just read all of the posts and not single person mentioned a cook book!!!!
I would suggest going to a book shop (on the street) and buying "The Cranks Cookbook" it's the best starter book out there with myriad recipes to start being vegetarian (ignore the Vegan militia of the millennial generation they know essentially nothing and buy mostly pre packed processed food). The Hemsley & Hemsley books are entertaining and Hugh has some good recipes in his book River Cottage Veg
Once you know the basics of how to use Pulses and Nuts in place of common proteins. Balancing the flavours etc and making a genuine decent Stock it all becomes super easy.
I'm not actually Vegetarian but my diet is 90% Veggie as I grow the vast majority of my produce and only buy my food from our local Devon butcher and anything else I can catch and kill.
Just try and steer yourself away from the mass produced quorn/mcartney and other vegetarian replacement products you see out there on the market they are the antithesis of what vegetarianism and veganism are about.