I have forgotten how to make gravy

I haven't had disasters recently, primarily because I've been too busy at work to spend lots of time at the oven. I know, cooking is supposed to be quick, but not when you're a poor cookist.

Today, I cooked a gammon roast. I put the gammon joint on the pan insert, poured some cola into the base of the pan and started roasting it covered by some tin foil.

The gammon wasn't huge, so I started peeling potatoes immediately. While they were parboiling, I peeled carrots and chopped some onions.

When the potatoes were soft, I poured the water out of the saucepan, salted & oiled them, shook them to generate some scrumbly bits and then poured them into the roasting pan (having removed the tin foil first.

I noticed that the cola hadn't evaporated, but it didn't concern me.

I added the carrots and onions, and put the pan back into the oven for another 45 minutes.

In the meantime, I boiled some broccoli.

After 45 minutes roasting, I removed the gammon and started serving the potatoes, carrots and onions with a ladle. Hmm ... this wasn't right. There was still lots of cola in the pan, so I served using the slotted spoon instead.

No problem, the cola would be infused with gammon juices, and I'll be able to make gravy with it.

The roasting pan was now empty apart from the liquid, so I dumped some plain flour into it and started stirring over a low heat. This caused the flour to immediately clump around the ladle, until it looked like a lump of mortar. I scraped the lump off the ladle with the slotted spoon and continued stirring. After a few seconds all of the liquid had disappeared, and I was left with burning lumps of mortar in the pan. Fortunately, I still had the liquid in with the broccoli, so I poured it from there into the pan. I now had a litre of broccoli-infused water and a lump of mortar.

After stirring, more stirring, and even more stirring, I had a litre of butterscotch-coloured water and lots of small clumps of solid matter. I couldn't work out how to mix it all together, to I poured everything from the pan into a jug, to enable me to use a whisk. The substance overflowed the jug, so I had to pour half of it away. Even using the whisk, it didn't improve the texture. I decided to taste it, to make sure I could still serve it. Unfortunately, it tasted like floury cola, so I had to pour it all away.

We had no scrumbly bits, as the potatoes had been drowned.
We had potatoes, carrots and onions tasting of cola.
We had no gravy.

My youngest daughter liked the flavour of the potatoes, though.

Blandness

As my cooking improves, I post less and less frequently here. Having said that, I have hardly cooked in the past week due to pressures of work, so I'm currently posting every time I cook!

I've just cooked Medallions of Steak with jacket potatoes and mixed veg. It was all fine, but bland. I need people to let me know how to make food interesting rather than simply nutritious.

The instructions on the polythene packaging around the steak were easy to understand, apart from the following line:

"Heat the pan on medium heat"
This is a frying pan, with olive oil in it, 2 minutes per side for rare steak.
When I have the dial on "high", the oil burns. When I turn the dial down slightly, it still burns. I need to turn it down approximately half way (I can't tell for sure if it exactly half way, as the gas burners don't appear to have any physical indicators as to the heat they produce at