Tempeh in a Port-Fig Sauce with King Oyster Mushrooms and Asparagus

We've been meaning to post about this dish for a long time because it was especially delicious. We started with the recipe from the vegan slow cooker, and then made lots of changes.

This is more or less the recipe we used:
3 Tbsp olive oil
1 large onion
6 cloves garlic
2 large king oyster mushrooms, sliced thinly (NOT at all similar to normal oyster mushrooms, these are super-thick stalked fatty mushrooms)
2 8 oz packages tempeh

fresh rosemary & thyme to taste (I used about 3 Tbsp of each, you could use a smaller quantity of dried herbs)
1/2 tsp black pepper

1/4 cup fig butter (we got this from Trader Joe's b/c we couldn't find fresh figs and the dried figs smelled bad)
2 cups port wine (we used a zinfandel port, in retrospect I would have used a drier port instead)
1 Tbsp balsamic vinegar
salt to taste
1 bunch chopped fresh asparagus, with the tough ends broken off

Heat the olive oil in a big skillet, add the onion and cook until soft. Add the garlic and mushrooms and cook another 3-5 minutes or so until the mushrooms are nice and fragrant (these mushrooms rock). Add the tempeh and black pepper and herbs and stir well, then pour in the port, vinegar, and fig butter (mix it up with the wine so that the fig butter dissolves). Add a bit of salt (you can add more to taste later), and wait for the whole thing to get hot again. Meanwhile, stir fry the asparagus in another skillet in a bit of olive oil, and take it off the heat immediately when it's done (this is easy to overcook, so it's best to cook it separately, but if you're feeling lucky or skilled with timing, just add it near the end of the tempeh simmering). Once the tempeh mixture has come to a nice simmer reduce heat and cook about 15-20 minutes until the tempeh has soaked up lots of flavor and the whole thing has thickened up a bit. Remove from heat, mix with the asparagus, salt to taste (and you may need to add more fig butter to taste as well) and serve with a nice wheaty bread.