Preheat the oven to 375F; brush the inside of a 2.5-quart casserole dish with olive oil.
Soak the rice in a bowl of lukewarm water for 30 minutes, and then rinse and drain.
Add the rice, 1/2 teaspoon salt, and 4 cups water to a medium saucepan.
Bring to a boil over high heat, then turn the heat down to simmer, cover the saucepan, and cook until the rice is al dente (it should still be a little chewy), about 15 to 20 minutes. Drain and set aside.
For the green beans, add a couple inches of water to a large skillet over high heat.
Once the water is boiling, add a generous pinch of salt, and then add the green beans; cover the skillet and cook 90 seconds. Drain and set aside.
Heat the oil in a medium saucepan over medium heat; add the onion and cook until softened and starting to brown in spots, about 8 minutes.
Add the garlic and cook 1 minute more. Stir in the cream cheese, 1/2 bag of cheddar shreds, milk, Worcestershire sauce, tamari sauce, black pepper, and remaining 1/2 teaspoon salt.
Turn off the heat when the cheese is melted.
Stir the green beans and red rice into the cheese sauce and then spread in the prepared casserole dish; sprinkle the remaining 1/2 bag of cheddar shreds on top.
Cover the dish with foil and bake until bubbling, about 20 minutes.