How to find a Nether fortress and farm blazes in Minecraft
A dense 7×7 grid of Torches on the spawner's level works, and so do fewer light sources of level 15 such as Glowstone, Shroomlight or Jack o'Lantern, placed so that…

Shroomlight is a glowing orange block that grows on huge crimson and warped fungi in the Nether.
It is mined with a hoe. It can be composted: each one has a 65% chance to add a layer to a Composter. It gives off light level 15.
It gives full light and breaks fast with a hoe. You find it among the caps of huge fungi, and growing a fungus with bone meal on nylium can produce more. Its warm glow is a natural light for organic builds.
This item has no crafting recipe.
A dense 7×7 grid of Torches on the spawner's level works, and so do fewer light sources of level 15 such as Glowstone, Shroomlight or Jack o'Lantern, placed so that…
Mining the block drops it.
It is a natural Nether light block from huge fungi.
The fastest tool is the hoe.
Yes. Each Shroomlight put in a Composter has a 65% chance to add a layer (the first layer in an empty Composter always works). After 7 layers the Composter gives Bone Meal.
Yes, light level 15.