Add a singular "setInput" method to IIngredients

src/main/java/mezz/jei/api/ingredients/IIngredients.java

@@ -18,6 +18,14 @@
  * @since JEI 3.11.0
  */
 public interface IIngredients {
+	/**
+	 * Sets a single recipe input. For recipes with only one input slot.
+	 *
+	 * @param ingredientClass The class of ingredient: ItemStack.class, FluidStack.class, etc.
+	 * @param input           The list of ingredients representing each input slot.
+	 */
+	<T> void setInput(Class<T> ingredientClass, T input);
+
 	/**
 	 * Sets the recipe's inputs. Each list element represents one slot.
 	 *

src/main/java/mezz/jei/plugins/jei/debug/DebugRecipe.java

@@ -15,6 +15,8 @@
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.GuiScreen;
 import net.minecraft.client.gui.inventory.GuiInventory;
+import net.minecraft.init.Items;
+import net.minecraft.item.ItemStack;
 import net.minecraft.util.text.TextFormatting;
 import net.minecraftforge.fluids.FluidRegistry;
 import net.minecraftforge.fluids.FluidStack;
@@ -43,6 +45,8 @@ public void getIngredients(IIngredients ingredients) {
 
 		ingredients.setInputs(FluidStack.class, Arrays.asList(water, lava));
 
+		ingredients.setInput(ItemStack.class, new ItemStack(Items.STICK));
+
 		ingredients.setInputLists(DebugIngredient.class, Collections.singletonList(
 				Arrays.asList(new DebugIngredient(0), new DebugIngredient(1))
 		));

src/main/java/mezz/jei/util/Ingredients.java

@@ -16,6 +16,11 @@ public class Ingredients implements IIngredients {
 	private final Map<Class, List> outputs = new HashMap<Class, List>();
 	private boolean used = false; // check that the addon used this at all. legacy addons will not
 
+	@Override
+	public <T> void setInput(Class<T> ingredientClass, T input) {
+		setInputs(ingredientClass, Collections.singletonList(input));
+	}
+
 	@Override
 	public <T> void setInputLists(Class<T> ingredientClass, List<List<T>> inputs) {
 		this.used = true;