cauliflower soup is gorgeous esp if you make it with milk and blend well. sprinkling of parmesan and toasted breadcrumbs on top. warming stale baguette in oven is perfect for making croutons to make it more interesting. use storecupboard spices to customise your croutons for each soup.
soups are great for eeking out vegetables, you can use the frozen broccoli to make a lovely green soup. frozen peas, lardons, creme fraiche and parmesan would make a lovely basis for risotto or soup.
cabbage, potatoes, stock, pulses, any frozen veg can be added to a basic mix of onions/celery/garlic to make a filling soup. pasta shapes or broken up spaghetti can be added near the end of cooking time. when serving add a blog of pesto to it and that gives you a lovely minestrone, eat with crusty bread. its a healthy filling meal.
I'd make a big veggie lasagne with the ingredients you already have. also the rice is enough to make a veggie stir fry, pea risotto with parmesan, pea fritters, bean fritters. Definitely make a filling dhal with the lentils. Chickpea curry is lovely esp with herby bread or spiced rice.
porridge may get boring but its so filling. have creme fraiche and jam in it one day, cinnamon sugar the next, just to make it different.
buy some suet and flour to make dumplings to bulk out meals. you could make veggie patties for breakfast if you get bored with porridge. also home made baked beans are wonderful, just use up tomatoes, puree and spices that you have. grated potato fritters, mix mashed potato and flour to make potato scones for weekend breakfasts.
baked potatoes. bake them, scoop out the flesh and leave the jackets intact. mix the potatoes with butter/milk/creme fraiche and whatever cheese you have. Spoon mixture back into jackets and bake for longer. top with any cheese you have left.