diff --git a/README.md b/README.md
index 50a1755..a22f982 100644
--- a/README.md
+++ b/README.md
@@ -16,3 +16,5 @@ A simple CLI tool to generate a static website from a
 - [ ] Add command to copy the embedded templates to an external
       directory.
 - [ ] Allow to read the templates from an external directory.
+- [X] Add a category metadata key.
+- [X] Sort recipes by name key.
diff --git a/cmd.go b/cmd.go
index 49deccf..7cba28d 100644
--- a/cmd.go
+++ b/cmd.go
@@ -4,6 +4,7 @@ type generateCmd struct {
 	Path             string `arg:"" help:"Path to the directory with the recipes."`
 	Output           string `default:"dist" help:"Path to the directory where the files will be generated."`
 	NameKey          string `default:"name" short:"n" help:"The metadata key for the recipe name."`
+	CategoryKey      string `default:"category" short:"c" help:"The metadata key for the categories."`
 	URLKey           string `default:"url" short:"u" help:"The metadata key for the recipe URL."`
 	Title            string `default:"Recipes directory" short:"t" help:"The title to use at the recipe index."`
 	IngredientsTitle string `default:"Ingredients" short:"i" help:"The title to use at the list of ingredients of each recipe"`
diff --git a/sandwitchboard.go b/sandwitchboard.go
index 19435c0..01d015f 100644
--- a/sandwitchboard.go
+++ b/sandwitchboard.go
@@ -17,6 +17,8 @@ import (
 	"github.com/aquilax/cooklang-go"
 )
 
+// ToDo: añadir la cantidad a los ingredientes y timers, quizá en un
+// X-data-quantity
 const (
 	stepPrefix       = "<p>"
 	stepSuffix       = "</p>"
@@ -28,11 +30,6 @@ const (
 	timerSuffix      = "</span>"
 )
 
-type RecipeFile struct {
-	Name string
-	Path string
-}
-
 //go:embed templates
 var embedTmpl embed.FS
 var imageExtensions = []string{".jpg", ".jpeg", ".png"}
@@ -98,6 +95,8 @@ func recipeImage(recipepath string) string {
 	return ""
 }
 
+// ToDo: si tengo "una cebolla en la #olla" me parsea
+// "ceb<span>olla</span> en la olla"
 func hydrate(text string, elements []string, prefix, suffix string) string {
 	cursor := 0
 	for _, el := range elements {
@@ -206,7 +205,8 @@ func (g *generateCmd) Run() error {
 		return fmt.Errorf("cannot create directory on path %q: %w", g.Output, err)
 	}
 
-	recipeFiles := []*RecipeFile{}
+	recipeFiles := map[string]string{}
+	categoryMap := map[string][]string{}
 	walkErr := filepath.WalkDir(g.Path, func(path string, d fs.DirEntry, err error) error {
 		slog.Debug("Walking through file", "path", path)
 
@@ -267,17 +267,24 @@ func (g *generateCmd) Run() error {
 		if url, ok := recipe.Metadata[g.URLKey]; ok {
 			recipeURL = url
 		}
+		category := ""
+		if cat, ok := recipe.Metadata[g.CategoryKey]; ok {
+			category = cat
+		}
 
 		htmlPath := filepath.Join(filepath.Dir(relpath), fmt.Sprintf("%s.html", filenameWithoutExt))
-		recipeFiles = append(recipeFiles, &RecipeFile{Name: recipeName, Path: htmlPath})
+		recipeFiles[recipeName] = htmlPath
 		recipeDistPath := filepath.Join(g.Output, htmlPath)
+		categoryMap[category] = append(categoryMap[category], recipeName)
 		data := map[string]any{
 			"name":             recipeName,
 			"url":              recipeURL,
+			"category":         category,
 			"recipe":           recipe,
 			"path":             path,
 			"relpath":          getRelpath(relpath),
 			"nameKey":          g.NameKey,
+			"categoryKey":      g.CategoryKey,
 			"urlKey":           g.URLKey,
 			"ingredientsTitle": g.IngredientsTitle,
 		}
@@ -302,8 +309,17 @@ func (g *generateCmd) Run() error {
 		return fmt.Errorf("cannot copy style.css: %w", err)
 	}
 
+	// sort categories
+	categoryList := []string{}
+	for category, recipes := range categoryMap {
+		categoryList = append(categoryList, category)
+		sort.Strings(recipes)
+		categoryMap[category] = recipes
+	}
+	sort.Strings(categoryList)
+
 	// generate index
-	data := map[string]any{"title": g.Title, "recipes": recipeFiles}
+	data := map[string]any{"title": g.Title, "recipes": recipeFiles, "categoryList": categoryList, "categoryMap": categoryMap}
 	indexpath := filepath.Join(g.Output, "index.html")
 	slog.Debug("Executing index template", "title", g.Title, "recipes", len(recipeFiles), "indexpath", indexpath)
 	if err := executeTemplateToFile("index", data, indexpath); err != nil {
diff --git a/templates/index.html.tmpl b/templates/index.html.tmpl
index 35ad5d9..29d9f3c 100644
--- a/templates/index.html.tmpl
+++ b/templates/index.html.tmpl
@@ -12,12 +12,19 @@
       <div id="content">
         <h1>{{.title}}</h1>
 
-        {{if ne (len .recipes) 0}}
-        <ul>
-          {{range .recipes}}
-          <li><a href="{{.Path}}">{{.Name}}</a></li>
+        {{$categoryMap := .categoryMap}}
+        {{$recipes := .recipes}}
+        {{range .categoryList}}
+          {{if (ne . "")}}
+          <h3>{{.}}</h3>
           {{end}}
-        </ul>
+            {{$recipeList := index $categoryMap .}}
+
+            <ul>
+              {{range $name := $recipeList}}
+              <li><a href="{{index $recipes $name}}">{{$name}}</a></li>
+              {{end}}
+            </ul>
         {{end}}
       </div>
     </main>
diff --git a/templates/recipe.html.tmpl b/templates/recipe.html.tmpl
index c1aa431..e1d9fa1 100644
--- a/templates/recipe.html.tmpl
+++ b/templates/recipe.html.tmpl
@@ -26,9 +26,10 @@
         <ul>
           {{$m := .recipe.Metadata}}
           {{$nameKey := .nameKey}}
+          {{$categoryKey := .categoryKey}}
           {{$urlKey := .urlKey}}
           {{range $k := sortedMetadataKeys $m}}
-            {{if and (ne $k $nameKey) (ne $k $urlKey)}}
+            {{if and (ne $k $nameKey) (ne $k $categoryKey) (ne $k $urlKey)}}
             <li><em>{{$k}}:</em> {{index $m $k}}</li>
             {{end}}
           {{end}}