You can save a shopping list into Tesco, and reorder it as you need to. I find that useful to order a set amount of milk, bread, salad for example, then add meal stuff on top.
Filled pastas are very easy- dried tortellini don't need to be in the fridge, cook in boiling water about 5 mins, yummy with a little pesto or a knob of butter.
Also, make a gravy of softened onions, coconut milk powder (Maggi) garlic and ginger cubes (frozen) add rice noodles and cooked chicken or prawns. Again, only takes 10 mins.
I second the slow cooker. I don't Brown anything, just bung it in and leave it on. Put the left overs in the freezer for another night.
Frozen prepared veg are a lifesaver too. Onions spinach and peppers, garlic ginger chilli, all sit in the freezer until you need them.
So put a layer of dried pasta in an oven dish. Pour over a tin of tomatoes and the same tin of water, add a pinch of mixed herbs. Sprinkle on some onions and peppers, sweet corn. Cover with grated cheese (you can buy it grated). Bake for 45 mins. Lovely. Add some chorizo or peperami before you cook it if you like.