Chickpeas, lentils, beans!

Edit: although these thing are pretty common for a fair chunk of the planet

Easy veggie soup with brown rice. Take desired vegetables (I like yellow squash, zucchini, celery, potatoes, carrots, onion, garlic), chop roughly, add to instant pot, cover with water, pressure cook on high for 10 minutes. When done, spice it to taste now that you can actually tell the flavor. Use slotted spoon/spider to remove veggies, set to side. Extract 4 cups of the broth, add it to rice maker with 2 cups of brown rice. While your rice cooks, put half of the veggies in a blender, blend until smooth. Add remaining veggies back to the pot with the blended veggies. Stir in some sour cream to make it creamy. Serve it over the rice.

Can also skip the rice, use corn starch to thicken a bit, and serve it with pimento cheese and crackers. Sub brown rice for wild rice. Throw in some chicken. Use different veggies. Triple the potatoes instead of other thickening methods. Possibilities are virtually endless. It's a different soup each time, which helps with variety. Excellent recipe if you grow squash, because them suckers are prolific.

Easy tacos:

Half a pound ground beef, large can of Rotel diced tomatoes with green chilies. Cook and drain the beef, add tomatoes and heat. Place corn tortillas (real ones, not those yellow "taco shells") in a lightly greased skillet and cook on one side for 30 seconds. Flip tortilla, add cheese of choice (sharp cheddar, various supermarket "queso," I prefer Oaxaca), cook another 30 seconds. Add to plate, spoonful of the meat/tomato mix. On the side, spoonful of sour cream with smoky hot sauce mixed in. Putting it on the sides prevents it from cooking off your taco too much. Dip and enjoy.

Top Ramen is just about the only thing I could purchase for $2. Just for context, the cheapest loaf of bread I can buy is $3.

I've been doing this for a while.

Buy a good five liter pot and ten pint sized containers. Make a pot of your favorite soup/chili/stew. Fill the containers and freeze. A good hot meal you can zap anytime.

For myself, I like bannock or fry bread (amount of fat in the pan is one of the big deciding factors on which it is). Kinda like a cross between a pancake and an American biscuit. To make it, you just need to make a quick bread dough and pan fry it. Roughly 2:1:0.6 flour to water to baking powder and some salt. Mix, divide into smaller portions, and pan fry. That's it. Using a whole grain and/or bread flour adds extra nutritional value.

Top with butter and or jam. Eat with fruit or vegetables for a balanced meal.

Velveeta Shells & Cheese, 11oz Pouch of Tuna, 10oz bag frozen peas.

I'm not sure about the exact price but it's one of the cheapest dishes i can imagine where i live.

(slightly modified) janssons frestelse, traditional swedish christmas gratin

just chop some potatoes into sticks, slice some onions thinly, empty both into an oven-safe dish, season to taste with black pepper and mix it all up, mix up some fish sauce and milk and pour as much as you feel like into the gratin (i think normal is like, 2/3rds?), some breadcrumbs ontop, and into the oven at like 200°C until it gets some colour.

use actual anchovies if that's cheap and you like bits of fish, and chopped up sun-dried tomato works great too (but that's expensive here).

Red beans and rice, or Cincinnati style chili. If you want cheap tasty and quick think of stews and sauces that will keep for about a week that you can split with a starch. I have maybe 10 dollars of ingredients in both of those dishes, and each one will get me 2 dinners and 5 lunches. Easy to cook too, basically cut your stuff up, plop it in a pot and add heat. No fancy cooking techniques or tools required.

I grew up with polenta, so that's an easy cheap meal I have.

For one serve mix roughly 3/4 cup of polenta with roughly 2.5 cups of water. Stir in a pot over a stove for about 10 minutes and you're done.

It's around $1 AUD per serve by itself. I usually add cheese so it's a bit more for me.