Asklemmy

I quite like cottage pie (or shepherds pie, depending on my mood). I've found mixing sweet potato into the mashed potato topping makes a HUGE difference. Only 1/4 to 1/3 is needed, anymore and it can be overpowering.

Marmite.

Soy sauce makes everything better. If there is some kind of sauce or broth just add a little bit. The extra salt and umami flavor elevate everything. Doesn't matter the cuisine. It goes great in burgers

New Mexico hatch Green chilies on everything.

I do a chicken pizza using tzatziki as the base sauce instead of tomato. Initially I was going to have it on top, but decided to go nuts. With the other Mediterranean ingredients on it, goes deliciously.

It's not that wild, but I absolutely LOVE blue cheese in a burger.

A quarter-dash of cinnamon in anything that calls for ground or minced beef. Enhances the savory notes of the rest of your seasonings and broths. (Haven't tried this with pork yet; but considering the existence of molé, I expect it to work with chicken too.)

Dry sherry in tomato sauce, soups, or anything with beef in it.

Butter. Butter. More butter. More butter, more better

Other than MSG - garlic powder, lemon pepper, paprika, and gochugaru. Almost everything I cook has those 4 put in, with only the lemon pepper reduced if citrus is not part of the dish.

Bog standard "all purpose seasoning" in mac n cheese. Just elevates the whole thing.

Worcestershire sauce in tuna. It is delicious.

Balance acidity, that's pretty much how to make every sauce delicious. Per OP's suggestion, that free glutamate punch also helps.

Recently discovered the wonders of yeasty flakes, never thought to put it in sauces (only sprinkles) so I will give this a go, thanks!

My ultimate sprinkly pasta topping is a mixture of grated cheese, crushed Salted crisps, yeast flakes, fresh basil, hot sauce, and Japanese shichimi.