2-1/2 lbs. cucumbers, peeled, center of seeds removed, and finely diced
1 large yellow onion, finely diced
1 small red pepper, finely diced
1 small green pepper, finely diced
3 cloves garlic, finely diced
1/4 cup salt
3 cups white vinegar
1/2 tsp. turmeric
2 bay leaves
1 tbsp. yellow mustard seeds
2 tsp. celery seeds
Place cucumbers, onions, peppers, and garlic into a large mixing bowl. Combine with salt and pour water over mixture until covered. Let sit for at least 6 hours or overnight.
Drain the cucumber mixture in a colander, rinse with water and drain again
In a large pot, add vinegar and spices and bring to a boil. Reduce the heat to medium-low and simmer for 5 minutes. Add the drained cucumber mixture and return to a boil. Reduce the heat to medium-low and simmer, uncovered, for 10 minutes. Discard the bay leaves.
Ladle the hot relish into hot, sterile jars, leaving ¼ inch of room at the top. Seal tightly with lids.
Process the jars in boiling water for 10 minutes.
Store jars in a cool, dark place for up to a year. If seal is broken, relish will keep in the fridge for about a month. Best eaten at least a week after making.