Bad Manners and Brimstone

Some ideas in random order:

Sauce for your chicken breast: Pan-fry your chicken in butter or your preferred oil. When done, remove chicken and add some liquid (broth, wine, fruit juice, anything that goes flavor-wise with the chicken). Dissolve any brown bits from the pan in there. Make a slurry from corn starch and water. Add slurry to pan, boil until thickened.

Roast or grill your chicken after rubbing it with herbs/spices/mustard/...

Half beer, half soy sauce makes an awesome marinade for grilled tri-tip (and would likely work for chicken, too).

Fingerling potatoes: Season with salt and whatever other spices or herbs work with the other dishes. Drizzle with olive oil. Bake at 350F dor 35 minutes.

A lot of Asian dishes should work for you as the starch is usually rice. Just stir-fry some mix of meat and veggies, add some liquid, perhaps a bit of cornstarch and serve over rice.

Smash up several cloves of garlic with some salt. Stir in plenty of olive oil. Drizzle over steamed brokoli or sliced-lengthwise, grilled zucchinis (while veggies are still hot). Marinate overnight in the fridge. Serve cold.

Season mashed potatoes with nutmeg instead of pepper. And of course make them from scratch with whole milk and a bit of butter.

Lots of fun things you can do with a pork tenderloin.

If you don't own a lot of cookbooks or cooking magazines, I'd get a bunch from the library for inspiration. There is really a lot you can make with those restrictions. It doesn't have to be bland and boring.

And there are a lot of non-boring recipes that are still pretty easy and fast to fix, so you can stay away from prepared foods that contain offending allergies. It just requires some planning like looking up recipes in advance and adding the required ingredients to your grocery shopping list.