Strainer insert for the Tupperware 2L "Slim Line" Pitcher.

Designed for cold brewing tea, but might also work with hot drinks.
You have to decide for yourself if you consider this food-grade and if you want contact with hot drinks.

Modelled to be friction-fit in TPU and held in place by the side-recesses and the lid.
Fits and seals well, albeit a bit hard to remove (with TPU you can just push in one corner until another one pops up, with rigid filament it might get stuck in there).

Adjust the main body to 0 top and bottom layers and infill of your choice to adjuct the strainer / sieve effect.
I used 40% honeycomb to minimize gaps between layers and get a uniform grid, works well, don't know yet how well it will clean in the dishwasher though.
The "rim" is included as a modifier to set walls or top/bottom layers (just setting walls but no top/bottom for me gave weird infill artifacts on the topmost layer, so I set it to 100 concentric top layers, that worked well).

Also the middle part is offset by 0.2mm (one layer) from the build plate to avoid the pattern getting squished and partly sealing.
Still adhered to the PEI sheet well with TPU, if you don't want that just cut it off in the slicer or modify the clearance height in freecad to a very small value. 

The freecad part is partly parametric, the heights can be adjusted via the spreadsheet, but the spline of the outline was generated in python and imported to fit a manual trace and does not like being scaled, so you should probably change XY dimensions in the exported 3mf/stl if necessary.