In medium-low heat, toast whole cumin, coriander, & fennel in a dry frying pan.
Remove from heat after the seeds turn brown and set aside.In a skillet or pan, heat butter until melted.
Add sliced bread and brown on both sides then set aside.
In a medium bowl combine avocado, lemon juice and one teaspoon of the salt. Mash together until creamy.
Top each bread slice with mashed avocado then top with tomatoes, spices, and remaining salt. Slice in half and serve.
