No I know thats not possible. Just having to use linux to compile the linux kernel is a pain for me.To what end? It's not like you can replace Darwin with the Linux kernel and get OSX with a Linux core?
We regularily cross-compile Linux kernels on OS X to various target architectures (mainly MIPS and ARM, but also sometimes to embedded PowerPC targets) and it's perfectly possible but non-trivial to get working initially.
You will need an appropriate cross-toolchain (targeting <your-target-arch>-elf) and a number of userspace tools installed. From the top of my head, you will need ncurses for "make menuconfig", need to modify scripts/kconfig/lxdialog/check-lxdialog.sh to recognize .dylib files (again only, if you want to do a "make menuconfig"), and generally work around a lot of issues in the scripts subdirectory.
If you are only starting with Linux kernel development, native compiles will be a lot simpler than cross-compiles, though. And Linux-hosted cross-compiles will be simpler than OS X-hosted cross-compiled.