Mustard and cress? Put a damp paper towel on a saucer, spread the seeds over, check every day, and add water to keep it damp (but not wet.) Should start germinating in a few days. One of them takes a couple of days longer than the other to get growing, but I can't remember which way round.
Mung beans? Same method as m&c. Other salad seeds like alfalfa and so on should also work.
Broad bean in a jar against a damp paper towel? Roll a paper towel round the inside of the jar, to line it. Get it damp. Stick the bean down between the side of the jar and the towel. Make sure the towel stays damp, but not wet. Again, you should start seeing progress in a few days.
Most dried pulses should work like this, either on a flat dish like the mung beans, or down the side of a jar.
You could also do thing like an avocado stone, in which you stick 3 or 4 cocktail sticks to suspend it over a jar of water, the base touching the water. Keep the water topped up, so it's still touching the avocado, and if the water starts turning green, empty it out and replace with clean water. You should start getting a root from the bottom, and then a stalk from the top, and eventually leaves, and then you can pot it up into compost, but this takes longer than the salady stuff above.