Broadly, what are the alternatives for connecting external memory to an STM32 eval board

[DSwar.2]

I'm interested in either connecting external memory to an eval board or getting an eval board with external memory already on it. I'm most interested in PSRAM, but other forms of memory may do. My main focus ins STM32H7, but if there is a solution for STM32L4+ or STM32L5 (eventually U5), that would be good. If I must get a chip, is there a recipe for connecting to nucleo–maybe board?

[Tesla DeLorean]

You're likely going to want to get deeper into the Reference Manual related to the connectivity afforded by different chips. Further examples can be found via the DISCO and EVAL series board schematics. On NUCLEO's you're going to have to identify the pins required for the interfaces. The NUCLEO-144 can typically support SDCard or eMMC via SDIO/SDMMC interface, and QSPI memories usually NOR Flash and NAND Flash via 6-pin interface.

Example boards with SDRAM, QSPI, SRAM and NOR FLASH

https://www.st.com/en/evaluation-tools/stm32h743i-eval.html

Example board with PSRAM

https://www.st.com/en/evaluation-tools/32l4r9idiscovery.html