- Using a food processor, pulse together potato flour, brown rice flour, flaxseed, thyme, salt and pepper until combined. Add butter; pulse until butter is size of peas, about 10 pulses. Blend egg with 4 tbsp (60 mL) ice water. Add to food processor; pulse just until dough comes together. If dough is still dry, add more water, 1 tbsp (15 mL) at a time.
- Preheat oven to 375°F (190°C). Crumble dough evenly around a 9-inch (23 cm) non-stick tart pan with a removable bottom. Using fingers, press dough to evenly cover bottom and side of pan; smooth surface by pressing with bottom of a measuring cup. Prick dough all over with a fork. Bake until golden brown, about 20 minutes. Let cool in tart pan on rack. Reduce oven to 350°F (180°C).
- Meanwhile, in a large pot, cook spinach with 1/4 cup (60 mL) water over medium heat, stirring occasionally, until wilted, about 3 minutes. Drain well; let cool. Lay spinach in single layer on a tea towel; roll towel into a log. Twist and squeeze towel to drain as much excess water as possible. Coarsely chop spinach and transfer to a large bowl. Dry pot and return to heat; add 1 tbsp (15 mL) oil. Sauté shallots and zucchini until softened, 3 to 4 minutes. Add to spinach.
- Whisk together egg, goat cheese, salt and pepper. Add egg mixture to spinach mixture; gently stir to combine. Pour filling into prepared tart shell; spread evenly. Bake until egg is set, about 20 minutes.
- Let cool in tart pan on rack to room temperature. Garnish tart with prosciutto (if using). Drizzle with remaining oil to serve.
DISCLAIMER. As product ingredients occasionally change, customers diagnosed with celiac disease or gluten sensitivities, or those wishing to avoid gluten-containing products, should be careful to always verify the gluten-free status of a product by checking the label and by consulting the Pocket Dictionary – Acceptability of Foods & Food Ingredients for the Gluten-Free Diet, 2012 edition, Canadian Celiac Association. The information provided is not a substitute for professional medical advice. If you have specific needs, please see your health-care provider.