easiest way to grow asparagus?

Patience, mostly. Buy one-year crowns rather than starting from seed, and plant them in a trench about 20cm deep in a sunny bed you won't want for anything else - they'll be there for fifteen or twenty years. Keep it weeded, they hate competition. Don't cut anything the first year, only a few spears the second, then a proper six weeks from year three. Stop by early summer and let the ferns grow up, that's what feeds next year's spears.