It's not essential for the toddler to have cereal and milk for breakfast. Or things involving spoons.
Mine feeds himself any combination of the following
Chopped cold sausage (chipolatas are good. If your DP makes this the night before he can save a couple and microwave them for himself with a nap, there's his breakfast sorted too)
Dry Cheerios and a non spill cup of milk
Chopped strawberries, melon and blueberries - I chop a load up every 2-3 days and we both snack on it.
Small chunks of cheese and pear in a bowl.
An oatcake spread with Philadelphia.
Leftover potato made into a Spanish omelette and cut in chunks. This is also fine made day before and whipped out of the fridge.
A banana
Toasted pitta bread slices and yoghurt to dip them into.
Dry muesli. He will pick through it for ages looking for currants.
Cut up toasted bagel With Philly or peanut butter.
Big splash mat under the IKEA wipe clean less than fifteen quid high chair is your friend.
Mine gets plonked in chair with any of the above and a truck, while I boil kettle, slam toast in or grab cereal. At the very least a handful of Cheerios buys you ten minutes which is all you need to prep something for yourself and the toddler. All else fails, YOUTUBE has Peppa Pig episodes on and each one lasts five mins.
you can always give cereal or porrdge at some other point in the day if you feel strongly about it.