Stock OR Water + Stock Cubes/Powder (any kind, I use chicken)
Preparation
Chop the onions, bake in your pot until glassy.
Chop and add bell pepper, bake until softened.
Strain the beans and corn, add to the onions and bell pepper. Add spices, mix and let cook for a few minutes, covered so the juices don't evaporate. Spices are to taste, but I use a lot of smoked paprika, garlic powder, onion powder, and a bit of cumin.
Add rice. Eyeball the amount. More than half but less than a full cup is a decent bet.
Add stock/water + stock cubes/powder. Barely cover the rice and vegetables, at most a knuckle water on the surface.
Let boil for 15-20 minutes. Check on it at least once and preferably more often to make sure the rice still has enough water to cook in.
If you used the perfect amount of water, the rice should have absorbed it all by the time you're done cooking. If you used too much, you'll have to strain it. If you used too little, there will be layer of burnt rice on the bottom. Don't eat that.
While the rice is cooking, chop the chorizo into little cubes. Mix through the warm rice after it's done boiling, and let it sit for a few minutes so the chorizo can sweat a little, increasing its flavor and warming it up.
Tips
You should probably wash the rice, but I can never be bothered.
This recipe is versatile and can be adapted to pretty much any vegetables you want.
I like to add cauliflower; if adding cauliflower, add it in small pieces and only in the last 5 minutes of cooking, so it doesn't turn to mush.
You can easily leave the chorizo out and choose to use vegetable stock if you want to turn this recipe vegetarian.