I would like to make choux pastry, and the recipe I have emphasises bringing the pan quickly to a boil after the butter has melted into the water at the beginning of the procedure.
I only have electric hobs available, which can take a few minutes to go from a simmer to a proper boil.
Will this have a negative impact on my pastry, and if so is there a way I can work around it?
Unless there is something seriously wrong with your stove, you should not have any negative effects from using it to make choux pastry. Simply melt the butter into the water over medium then adjust the temperature to high.
The purpose of boiling the water and then cooking the pastry over low heat is to gelatinize the starches in the flour. Your recipe likely adds emphasis to the point of bringing the water to a boil quickly so that you do not simmer the water away. Doing so can have negative effects on the finished product because it will throw off the water:flour ratio and you will not be able to completely gelatinize the starches.
If your stove heats up so slowly that you think this might be an issue, you can simply place a lid over the pot as you bring it to a boil, making sure to add back to the pot any condensed vapor on the inside of the lid.
I really don't think it's necessary for this application, Didgeridrew's advice regarding the pastry seems spot-on to me. However, if you really want an instantaneous temperature change for any reason and you're stuck with a problematic stove, you can make that change if you can control individual burners separately.
Keep another burner set to "high" while you're working on the burner set to "low". Then when you want a quick increase in the heat level, you just switch burners. (Hobs = Burners, right?) You only need to keep the "high" burner on for the length of time it takes to heat, or just keep a pot of water boiling on the "high" burner until you're ready to make the swap. Of course, the process works just as well in reverse.
If you cannot make your electric cooktop work satisfactorily:
-Single induction hobs or camping gas stoves (disclaimer: some aren't certified for indoor use. And the induction plates are stronger anyway) are available around €30/$30 in most places.
-You could use a kettle (or a pot on another hobplate) to boil the water before you add it to the butter - or if that has unwanted side effects, melt the butter with less water (careful, can splatter!), then fill up with hot water.
