Baseline reference quantities:
Total flour: 600 gms
Total water: 500 gms
Salt 8-10 gms (can be lowsalt/fine ground sea/rocksalt mix)
Optional (merest drop of oil, olive walnut or ricebran)
Active sourdough starter 80 - 120 gms (less is more sometimes for a slower but better rise)

Required: Large/very large mixing bowl; plastic curved mixing spatulas; platform scales (that can be easily tared, e.g digital)

Basic steps: Prepare sourdough; Weigh out and Mix flour salt and oil in bowl; Autolyse flour; Add sourdough starter to hydrated flour and mix; Stretch dough 3 to 4 times over 1 to 2 hours; Allow to bulk rise; Fill tin or moulds; Bake.

1) Remove sourdough* container (mines' in Kilner jar) from fridge, mix your normal flour/water in (Mine's like doubling its usual volume with 3/4 tablespoons of light rye/white flour mix and a splash of water) and allow to warm and become nice and active within a couple of hours typically (can rise and double in volume!)

2) Layout tools including very large mixing bowl, measuring jug for water and mixing/stretching spatulas, spoons, digi platform scales etc.
Mix your flours (Shipton 3 seed malted or favourite mix) , tare the bowl and add 600 gms. Add typically 10 gms of fav salt (and 5 of oil but not essential)
Mix well with spat or large spoon and then add 500 ml of cool water. Use spatula to throughly mix to 'wet' all the flour creating a dough...smooth over with wet spatula. Cover with clingilm and leave for 1 to 2 hours to Autolyse (hydrate and activate the flour)

3) Stretch gluten/ do not knead.
Put bowl on a suitable surface and with the curved bowl spat, start gathering underneath dough, lifting, stretching, sticking down over itself. Constantly rotate bowl on surace working around the periphery for about 5 minutes collecting, stretching, sticking back down without knocking about or kneading.
Leave for about 1/2 hour to rest.

4)Repeat 3) at least twice more, noticing the dough bulks up between stretching and becomes silkier and much smoother.

5) Do one last time and cover, leaving for a good hour or more until a noticeable bulk rise to twice its original volume at least.

NB. Each time 3,4,5 carried out, ideally finish stretched dough off (with wetted spatula) to a smooth low dome shape in bowl.
Judge workability and hydration, whilst stretching a wetted spat can add more hydration if required.

Now, zis eez ze interesting beet! Or frightening and most difficult bit. However its more a head problem than a practical one... filling the moulds or tin.

Scoop or pour (usually very wet sticky) dough from bowl into large 2lb/ 1 kg tin or the two the silicone moulds, balancing up the two on scales if necessary.
I tend to grab a wedge of dough between two of the spatulas and lower it into the moulds. When balanced up quantity wise, wet spat again and stipple or pat the dough level along the tin.

*Recipe assumes you have created a soudough starter and typically keep in a jar in fridge.

Notes:

Variations(flour, salt, water quantities, dividing, baking etc)