Porcini Mushroom, Greens, and Forbidden Rice Gratin

Comfort food with extra veggies in this flavorful and hearty Porcini Mushroom, Greens, and Forbidden Rice Gratin. Packed with umami flavor this gratin features sweet caramelized onions and black rice, with meaty mushrooms and kale adding richness and veggie goodness. Gruyere cheese and crispy bread crumbs tie all the flavors together. 

A Comforting Gratin

Have you tried black rice (also known as Forbidden rice)? Its texture is similar to short grain brown rice, it has an earthy, nutty flavor and sweet undertones. Black rice is considered a whole grain. It’s delicious enjoyed alone, but is absolutely wonderful in this gratin.

But let’s take a look at porcini mushrooms, too. Recipes with porcini mushrooms bring a rich, earthy and umami boost, as well as offer a meaty, chewy texture, like in my mushroom bolognese sauce. 

Look for porcini mushrooms at a well stocked grocery. You’ll find them dried in one ounce packets. They’ll need to be rehydrated (or reconstituted) before using them in this recipe. It’s easy to do. 

The Makings of a Black Rice Casserole

This gratin is also considered a casserole. It’s simply layers of various components put together in a deep casserole dish, then baked. The flavors marry to produce a rich and flavorful recipe, hearty enough as a main. We love this recipe with a big salad.

At a glance, here’s how to make it:

• First, reconstitute the dried porcini mushrooms by soaking them in hot water. Drain, chop and set aside. 
• Second, put the black rice on to cook.
• Third, caramelize the onions. 
• Fourth, destem the chard and kale, then cut into ribbons. Cook until wilted. 
• Fifth, toast the breadcrumbs and shred the gruyere. 
• Next, in a mixing bowl mix the mushrooms, black rice, onions, and greens. Transfer to a casserole, top with gruyere and breadcrumbs.
• Last, bake!

While the gratin is baking, now is a good time to whip up a big leafy green salad, and warm the bread. 

More About the Ingredients

Porcini (say it with me! ‘por-tchee-knee’) mushrooms can be found year-round in dried form, typically in 1 oz bags. I find them at my local Co-Op, along with forbidden rice (AKA purple or black rice). Either ingredient can be found at Amazon.com here and here if you’re unable to find them locally.

Traci’s Tips

• Porcini mushrooms and forbidden wild rice pair well because they both impart a nutty, umami flavor while the porcini also add a firm, meaty texture. Gruyère adds a bit of richness and indulgence.
• This black rice casserole calls for both Swiss chard and kale. However, use one or the other, or both! 
• This recipe is hearty enough to be served as a main, and would be lovely center stage on a holiday table. 
• Make it gluten free by using gluten free breadcrumbs. 

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Porcini Mushroom, Greens and Forbidden Rice Gratin

5 stars from 1 rating

By Traci York

Servings: 5 -6 as Main Dish

Comfort food with extra veggies in this flavorful and hearty Porcini Mushroom, Greens, and Forbidden Rice Gratin. Packed with umami flavor this gratin features sweet caramelized onions and black rice, with meaty mushrooms and kale adding richness and veggie goodness. Gruyere cheese and crispy bread crumbs tie all the flavors together. 

Look for porcini mushrooms on the natural food isle, dried. They'll need to be reconstituted.

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Ingredients

• ▢ 1 oz Dried Porcini Mushrooms, 28g
• ▢ 1 C Forbidden Black Rice, 194g
• ▢ 4 1/2 C Yellow or Sweet Onions, sliced into thin 1/2 moons (about 2 large onions) 344g
• ▢ 1 Tbs Coconut Oil, Virgin, Unrefined* (see note)
• ▢ 2 Tbs Butter, divided
• ▢ 1 tsp Sea Salt, divided
• ▢ 1 tsp Pepper, divided
• ▢ 2 1/2 C Kale, chopped, 104g
• ▢ 2 C Rainbow or Swiss Chard, chopped, 118g
• ▢ 1 1/2 C Bread Crumbs** Gluten Free if needed, 116g, see note
• ▢ 8 oz Gruyere, grated, 227g
• ▢ 1/2 tsp Fresh Thyme, chopped
• ▢ 1/4 tsp Nutmeg
• ▢ Fresh Thyme for Garnish

Instructions 

• Bring 2 C of water to boil. Place porcini in heat proof bowl and pour the boiling water over the porcini. Cover for 30 minutes to soften the porcini.
• Put the black rice on to cook. Fill stock pot with rice, a pinch of sea salt and 2 C water. Bring to a boil, turn the stove to low, cover and cook for about 30 minutes. When cooking is complete, the rice will be tender and no water will remain. Place rice in large mixing bowl. Set aside.
• Cut the onions in half and slice length wise so that your slices are thin and long. Melt the coconut oil and 1 Tbs butter in a large non stick sauté pan. Place the onions in the pan with 1/2 tsp salt and 1/2 tsp pepper. Cooking on medium to low heat, these will take about 30 minutes to caramelize. Don't rush them else they'll burn. Low and slow here. Stir occasionally.
• For the greens, wash the kale and chard. De-stem the kale. Ribbon the greens by rolling the leaves up, length wise, then cutting about 1/2" ribbons. Then, rough chop the ribbons in 1/2. Set aside.
• Melt 1 Tbs butter and mix it into the bread crumbs. Set aside.
• Preheat the oven to 375F (190C). After the porcini have softened, strain the porcini through cheese cloth, reserving the broth. Squeeze the cheese cloth so that the broth is extracted from the porcini. Give the mushrooms a good rinse in a sieve to make sure they are free from debris. Rough chop the porcini and place them in the large mixing bowl with the rice. Strain the broth through the sieve again. Measure out 1/3 C (80g) of the broth and set aside. Freeze or refrigerate the remaining broth for future use.
• When the onions are done caramelizing, add the greens to the sauté' pan, with the onions. This may be done in batches if needed. When the greens just start to wilt, pull them from the pan and put them in the large mixing bowl with the cooked rice and porcini.
• In the large mixing bowl, mix all the rice, porcini, greens, caramelized onions, 1/2 the grated gruyere, thyme, nutmeg, and 1/2 tsp salt and 1/2 tsp pepper. Mix to evenly distribute the ingredients. Taste to check seasoning. Now is a good time to adjust if necessary.
• Prepare a 3-4 Quart casserole by spraying it with cooking spray. Pour the rice/greens mixture in the dish, smoothing it out. Pour a 1/3 C (80g) of the broth over the mixture. Spread the remaining gruyere over the top, then top the gratin with the breadcrumbs. Bake uncovered for 25 minutes. Garnish with fresh, chopped thyme.
• Store in a covered container for up to three days.

Notes

*I use unrefined coconut oil for most of my cooking and baking. You will not taste coconut in the recipe. I reserve olive oil mostly for roasting, salad dressing, drizzling and dipping, but it can be subbed here if needed.

**For homemade breadcrumbs, process five pieces of bread in a food processor, then bake the crumbs at 325F (163C) for about 30 minutes, stirring once, to dry them out. Use gluten-free if necessary.

Inspried by The Smitten Kitchen Cookbook.

Nutrition

Calories: 612kcal | Carbohydrates: 74g | Protein: 25g | Fat: 25g | Saturated Fat: 15g | Cholesterol: 62mg | Sodium: 948mg | Potassium: 699mg | Fiber: 6g | Sugar: 9g | Vitamin A: 4799IU | Vitamin C: 55mg | Calcium: 617mg | Iron: 3mg

Nutrition is provided as a courtesy and is an estimate. If this information is important to you, please have it verified independently.

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