1) Add spices to the pan and toast them for 5 minutes over medium-high heat until they start to smell really good. They should turn slightly tan, but don’t let them burn!
2) Give them a quick whirl in spice grinder. If you wanted it really spicy, you could up the red pepper a bit and also add some cayenne.
3) Heat oil over medium-high heat in a large pan with a lid. Add onions and garlic and cook for just a few minutes until they are translucent. Then add all spices and stir well to combine.
4) Stir in rice. Stir everything together for about 30 seconds.
5) Add canned tomatoes and about 3 to 3 1/2 Cups water. Bring this mixture to a simmer and cook it covered over low heat for about 20 minutes.
6) To make tostados, add canola oil (or peanut oil) to a large frying pan until it comes about 1/2 inch up the side. Heat it until the oil is 350 degrees.
7) Once oil is hot, toss in one or two tortillas at a time depending on the size of your pan.
8) With some tongs, gently turn the tortilla over every few seconds to keep it as flat as possible.
9) Move the tortillas to a paper towel or a paper bag to drain off the oil and add some salt to them right away.
10) After 20 minutes or so, check rice and beans. Add beans near the end (drain them from the can) and also add a good pinch of salt and pepper.
11) Stack! Start with a layer of rice and beans. The basic layer is tostado, cheese, rice and beans, hot sauce (optional), and another tostado. Top the whole thing with sour cream and guacamole.