Can I lay brick onto porcelain slabs?

You can but the mortar won’t adhere to the porcelain slabs forming cracking. One trick of the trade you could do is mix PVA glue with sharpe sand and apply a thin coat to the porcelain slabs in the area of the step and allow to dry forming an abrasive bond allowing the mortar to bond when laying the bricks. Any more information required please don’t hesitate to ask.

I would not lay a course of bricks onto porcelain slabs personally as mortar will not stick to porcelain for very long and with foot traffic these will soon de bond over a short amount of time. Mark out desired brick course line using a spirit level and pencil and use a 4.5" grinder with Dimond blade to cut through the porcelain tile. Dust suppression is defiantly recommended. A good sign that you are through the porcelain and onto concrete is when the dust kicking out the grinder slightly changes colour, then you no that you are at the correct depth and this will help when lifting the tiles out from where the brickwork is to be bedded. A few layers of tape/not duct along the cutline will help with possible chipping of tile edge. Then use hammer and bolster to chip away tiles working carefully away from cut line. Try to remove all tile adhesive if possible. This is the best way for long-term results.

You'd be better off lifting the couple of paversout dig a wee track out for your concrete start you brick from there definitely not go wrong 👍👍

Yes as long as it’s a good surface area, in good shape and as long it doesn’t lift too

As long as your base underneath the slabs is solid and it’s just one step it will be ok.

Their is a prebaged slurry mix one uses to lay porcelain tiles onto the sand & cement background so I would assume the reverse is true ask the tile shop what the product is called don’t use pva it returns to its homogenous state when wet sbr or liquid latex can be used outside

Yes it would be ok as long as the patio has been done properly