[Hannah]: how (and why) to make pickled onions

My new husband the Urban Caballero/Companionable Atheist and I are trying to improve our home cooking. One of our big problems is that restaurant food is more flavorful than most of the food we make at home. Well, we know why this is, mostly: restaurants use more butter and oil. To compensate, we've started buying a lot of spice mixes to give ourselves more options for flavoring stuff. That said, our default strategies are still the following:

1) add more salt and pepper
2) add more lemon juice
3) add cumin
4) add raisins or craisins.
5) cook it in beef stock or chicken stock
6) toast the grains in the pan before you add liquid and cook them
7) add soy sauce (don't do this if you've already added raisins or craisins or if it's already salty)
8) add capers (again, not with the raisins, please)

This can get you a long way, but one of these days you might find yourself tired of cumin and raisins.

We also get a long way with this option:

9) add zhug

Now I've come up with another excellent topping, home made and it lasts a few weeks:

Pickled red onions. Steps:

1) cut 2 red onions into thin slices
2) heat in a saucepan to boiling: 2 cups white vinegar, 1/4 cup sugar, some cloves, a bay leaf, chili flakes
3) add onions
4) cook for 2 minutes
5) cool
6) pour into nonreactive container (we used a glass jar), put in fridge

These are pretty much great on everything (eggs, burgers, meat, rice dishes...). this week I've been eating them out of the jar with a fork.

Any other ideas - your go-to spices to make things interesting?