Finely dice onion and place in a large mixing bowl.
Chop almonds until very fine (but not until they are almond meal). Add to bowl.
Finely shred carrots in food processor and add to bowl. Mix in tahini.
Place rice and seasonings in food processor and pulse several times until rice in lightly chopped and ingredients are combined.
Transfer rice and seasonings to mixing bowl and mix all ingredients together well. Use hands if necessary to ensure that ingredients are very, very well mixed.
Pack very tightly into a well-oiled 1 1/2-quart casserole dish. Bake uncovered at 350° for 55 minutes to 1 hour.