The base recipe for my spinach pie (rough recipe I don't have a book) is    500g spinach 250g Feta cheese 250g Cheddar cheese 1 bunch of spring onions 1.5 - 3 eggs (for binding)   Baked into 2 large pies, made with filo pastry. Cooked at 180-200C.  Originally I would make this by using cooking fresh spinach in water, then carefully drying it with paper towel, and combining that with fried spring onion.  However the fresh spinach was too expensive, so I refined it. Changing to frozen, which I would put in the microwave, then while it was defrosting, I chop up the spring onions and put them into the microwave with it. I would not drain this or anything just combine with the other ingredients (in the same bowl I microwaved it in even!) This was great it made delicious pie and was low effort. You couldn't taste the difference.  However I wanted to make it more filling. so I tried adding potato, it was good and very filling. However, my family thought it was less full of spinach and feta goodness.  So my next approach was to double the amount of spinach and cheese.  It is delicious and as expected each slice is twice as filling.  I've tried that twice now and both times it has ended up soggy on the bottom.  What can I do about this? Is it a matter of squeezing the water out of the defrosted spinach? Or is there some other trick, like cutting a hole in the top of the pastry to let the steam out while it cooks. 
Are you overthinking this? A small teapot, sized for one person, would meet your criteria, wouldn't it? Unless you count the infusion basket separate from the teapot itself, you just have a teapot to rinse out (no scrubbing needed) and a mug to wash.   This is mine:   It holds around 20oz of water, so I can fill the pot, steep for a few minutes, then lift out the infuser basket and dump the leaves. You can easily do this in a breakroom or kitchenette area of an office, and then take the teapot back to your desk and voila, 3-4 cups of tea with one trip to the breakroom. Mine's made of cast iron and easily keeps the tea warm longer than it takes me to drink it. When you're all done, rinse out the teapot (cast iron won't need much more than a brief rinse) and wash your mug in the sink.   Based on my tea this afternoon (admittedly, taken in my home office today rather than at work):   It's super easy to clean out the teapot, I just ran water through it a few times. The infuser basket took a little more work, but no more than 30 seconds or so of running under the water to make sure I got all the leaves out. The teapot has a lid, to cover the tea while steeping. The infuser basket lifts out when the tea's done steeping. I was able to transport the pot by the handle from my kitchen to my office without any burns. It's a little warm, but not hot enough to burn you. I'd love to see the drop that damages cast-iron!   