Hull the strawberries and place them in a large saucepan, cut up any of the bigger strawberries so they will cook evenly.
Add the sugar, lemon juice, balsamic vinegar and ground black pepper to the strawberries. Give all the ingredients a good stir to mix everything evenly.
Place the pan over a low heat and using a potato masher give the strawberries a good mash to help speed up the breaking down of the strawberries.
Bring the jam up to a simmer, stirring until all of the sugar is dissolved. Turn up the heat and allow the jam to boil away for 8-10 minutes. Stir every now and again to be sure the jam isn't sticking to the bottom of the pan.
Boil the jam until it reaches 105C, allow the jam to cool a little and then pour it into sterilised jars, seal with a lid and store in a dark cupboard unopened for approx 6 months.
Prepare two baking sheets with baking parchment or silicone mats and pre-heat the oven to 140C/120C Fan/Gas 1.
Place the egg whites in the bowl of a stand mixer with a whisk fitted. Whisk on high until white, fluffy and very stiff. Slowly add the sugar a tablespoon at a time until it is completely combined. The mixture will change and become very shiny, thick and firm.
When the meringue holds a stiff peak, put it in a piping bag fitted with a French piping tip.
Pipe 6 spirals on each tray and pipe an edge around the next to give it a hollow in the middle - you might need to pipe two edges on top of each other, to give a deeper nest.
Bake in the oven for 30 minutes, then turn the oven down to 120C/100C Fan/Gas 1/2 for the last 30 minutes.
When the nests are cooked, place them on a wire rack to cool down.
Take the yoghurt and stir through a healthy amount of strawberry jam, however much you fancy until it is nicely rippled.
Take each nest and put a small layer of jam in the bottom, top with some of the yoghurt swirled with jam and then top with fresh strawberries.
Repeat with the remaining nests and serve immediately.
To sterilise jars - wash your jars in hot soapy water and then dry them in an oven pre-heated to 110C for about 10 minutes.